Bindings 101: How to mount Telemark bindings (Part II)

[Johnny]

Now that you have a supa-dupa, hyper-mega clear idea of Where to Mount Telemark Bindings, it's now time for drilling. Measure twice, drill once as they say. Here are some tips by Black Diamond, a company that doesn't make tele bindings anymore, that doesn't make telemark boots anymore but are still selling trendy 900$ made-in-China alpine touring skis.

"Mounting with telemark bindings is not recommended."
Black Diamond skis recommandation since 2015

PRECISION
This is paramount for telemark bindings, which have much higher peak loads than an alpine or AT binding. What is often overlooked is that the ISO standard minimum for binding pull-out strength for alpine skis is 292 pounds per screw, whichis fine for alpine binding systems but is not nearly enough for an active tele binding. Our pullout strength exceeds 440 pounds per screw, but that pullout strength is only achieved with a precision mount. For example, that strength drops 40% if the screw doesn’t thread in straight. How many times have you chased a screw hole that wasn’t completely in line with the binding and you just kind of forced it in, cocked over, until it snugged down straight? That's a major no-no.

TORQUE SPECS
Most alpine specs have around 4-5 Nm per screw when you are using a TLD (torque limiting device). For an active tele binding you need upwards of 8-10 Nm. Some company’s skis may not take this much, but for BD skis, feel free to crank it down this much (in fact you must on bindings such as the O1.) In addition, we recommend a 3.6 Ø drill bit to get the bestthread retention based on the minor diameter of the screw. This tighter screw fit also mandates a higher torque to get the screw into the ski, so again, the traditional TLD setting probably would not seat the screw tightly enough.

WITCHCRAFT
With tele there’s a bit of witchcraft at every corner. All bindings are not the same and in fact have drastically different forces associated with each. The boot size and skiing style greatly influence the degree of mounting sloppiness that can be tolerated. In addition, the screws, screw heads and shapes are different, and the industry lacks any sort of standard or unification, resulting in very specific mounting issues. For example: The tapered-head screws provided with K2’s older inserts work fine with BD bindings except for the O3, which requires a flat-head screw that interfaces with the plastic.

MEASURE
It’s important that you accurately determine your mounting location based on the recommended specifications with personal preference adjustments, if applicable or known. Measure twice, drill once. Again, things get complicated with tele. If you base all things off of the chord-center (or some reference point along those lines), different boot sole lengths will affect the mounting position and its relationship to the sidecut and overall length. The middle 26-27.5 is the baseline, shift 5 mm forward for 28.0 and up, and 5 mm backward for 25.5 and smaller. This keeps a good relationship between balance point of the ski and, most importantly, mid-boot in relation to the center of the sidecut.

CLEANLINESS
Be sure to remove any dust or shards from the drilled hole. It is important to use clean screws, without any chunks of material embedded from a previous mount. A screw with smooth threads ensures proper thread cutting when you turn the screw in. It is also important to apply adequate downward pressure when starting the screw so the threads cut immediately and don't spin and grind away the first engagement. Tapping the hole first is never a bad practice regardless of metal or not. When mounting thinner skis that require the screws to be ground down shorter, be extra careful to grind a slight taper and to avoid leaving any sharp burrs which will not cut a smooth thread into the ski.

EPOXY
We recommend using epoxy for all telemark mounts. Epoxy can increase your overall maximum pullout strength, but most importantly acts as a buffer to decrease screw-loosening possibilities. This in turn can lead to a degradation of the ski’s core and increase peak shock loads that will eventually result in the binding ripping out of the ski. For alpine and alpine touring bindings, if you don’t prefer epoxy, use simple wood glue to seal the hole and lubricate the screw as it is being twisted in to help achieve suitable clamping force for given torque values.

JIGS
Jigs are a great tool for precision tele mounts and keeping the heel block in the prescribed location every time or if you don’t have the actual boot to work with. (Sorry if you normally mount skis with the tips facing left. Perhaps you can stand on your head or mount behind your back, Jimi style.) Fully support the ski so that when applying drilling force you don’t flex the ski; this is crucial because it ensures that the holes are perpendicular. Some skis can get quite thin, so make sure your drill bit and provided screws are not going to dimple the base, especially at the heel block areas. We highly discourage any type of paper template mount as you will never achieve full strength and can also compromise the overall strength of your binding.

HOLES AND SCREWS
Each ski manufacturer has a recommended hole diameter and each binding screw design should have a specific hole diameter recommendation. Confused about which to use? Put down the drill and contact the manufacturer. If all else fails, use the binding recommendation and tap the hole. As a rule of thumb, the more expected force on the system, the higher torque the screws are going to need to resist the resulting binding force acting against it. When that relationship is out of whack, the screws can begin to loosen and even a single loose thread will dramatically affect pullout strength. It can also slowly degrade core-retaining properties by slight movements of the screw over time, again reducing pullout strength. Using torque limiting power drills is usually a bad idea unless you’re skilled in the art. We recommend hand tightening each screw with a TLD-enabled hand posi-driver, making sure that each screw goes directly and perpendicularly in and then doing a final torque spec twist on each screw. If for some reason you don’t have a TLD, hand tighten more than you think—pushing down with all your strength while turning the screw means that you’re probably at around 10 Nm.

RECAP OF THINGS NOT TO DO:

• - Don’t re-use old screws that have crap plugged in the threads. When you screw that into a new ski you
  are cutting crappy threads into the core and compromising strength.
  
  - If you need to grind screws for some reason (e.g., the ski is thinner than the screw design provided), be
  extremely careful not to leave any burrs—these will mess with the thread cutting of the ski core.
  
  - If you get a spinner and strip a hole, don’t half-ass it—fix it right by putting a heli-coil in.
  
  - Don’t reverse bend the ski when applying drilling pressure. Support it from beneath so that the screw hole is perpendicular to the ski. Even a small amount of flex will change the angle and you'll lose full pullout strength potential.
  
  - Don't grind out your initial hole threads by carelessly spinning the screw without downward applied force.

[TallGrass]

I don't see "which screws" and "which tool" mentioned. While the snark reply might be "whatever the manufacturer supplied", one may be on their own re-using a NLA 3-pin missing the fasteners, or might want to improve on what the manufacturer supplied. For this I offer a primer...

IF YOU READ NOTHING ELSE,
KNOW THAT THE UBIQUITOUS "#2 PHILLIPS"
IN EVERY HOME'S "TOOL DRAWER"
IS NOT FOR ANY SCREW THAT IS A "+" INSTEAD OF A "-" ,
AND USING IT ON HIGHER QUALITY ZIF TYPES WILL RUIN BOTH.


1. SCREW HEAD (TOOL) TYPES
2. SCREW HEAD SHAPES
3. SCREW THREAD TYPES
4. SCREW MATERIALS (METALS)
5. CONCLUSION


1. SCREW HEAD (TOOL) TYPES
The uninitiated might call everything with a "+" on top a "Phillips" and grab whatever "+" screwdriver is on the bench. However there are MANY TYPES and MANY SIZES of "cross-head" screws.

I divide them into two broad groups based on if they are ZIF (Zero Insertion Force), meaning you do not have to press down on the tool to keep it engaged with the screw.

Click for images of different screw head/driver types and differences.

Non-ZIF : Phillips, JIS I'm covering these first because they are the most common, AND because their (screw)driver tools are most often MIS-used on other types damaging both the screw and tool.

- Phillips Look closely at the flutes, each arm of the +, from the side and you'll see it is V-shaped so it cams out to avoid over-torquing. The #2 is the most common whereas 0-sizes are common on electronics. Sizes are often labeled on drive bits or handles with PH000, PH00, PH0, PH1, PH2, or PH3.

- JIS is short for JAPANESE Industrial Standard, and may be labeled "Vessel," a major Japanese manufacturer. Look for a "." stamped in the corner of the "+" screw. Next time you see an older Japanese motorcycle, look at the screw heads on the brake fluid reservoir on the right handlebar grip and they're often bugger because someone used a PH2 instead of JIS-2. JIS uses BOTH a different V-shape degree for each flute, but also a different angle for the "point" of the flutes coming together. When mixed Phillips/JIS, the driver will bottom out before fully engaging the flutes, or the flutes will only engage with the top edge of the screw hole never reaching the bottom. Often labeled JIS-1, JIS-2, and JIS-3 (perhaps JS1, JS2, ...), they are common on Japanese products, especially precision and mechanical items.

ZIF examples: Tip! If the tool/driver will stay standing vertical, feels like it locks in, or you can tilt the screw a few degrees without the driver (e.g. screwdriver: tip-shaft-handle) falling out, it's likely ZIF.

- Socket Cap (aka Allen, aka Internal Hex, hexagon insert for use with Allen Keys or bits). Sizing is in mm measured across the flat sides, not the points. If measuring, sizing is "nominal" (e.g. 8mm) but "actual" fudges a % for a "slip fit" (e.g. tool may measure 7.95mm and or hole 8.05). These work like hex-head bolts in reverse.

- Torx (aka Star Drive). Sizes are numbered but do not correlate 1:1 to metric. Prefixed with a T often increments of 5 above 10 (e.g. T8, T9, T10, T15, T20, ...). Do NOT confuse with Allens, nor inter-use drivers. Torx with a pin in the middle ("Safety Torx") are often used. Where Allen contact edges cam and can round out, Torx is more perpendicular to the axis of rotation like paddle wheel blades hitting the water perpendicularly.

- Pozidriv (It's TMed; not Pozi-drive nor Posidrive). Popular in GERMANY and EUROPE. Denoted by diagonal lines scribed in the head looking like the U.K. flag or X overlaid on +. There may be a square detectable in the middle. Unlike Phillips and JIS whose flutes are V-shaped to cam the tool out if over-torqued, the flutes on Pozi are flat with parallel faces. Sizes often labeled as PZ0, PZ1, PZ2, PZ3, etc.

- Square Drive Just like it sounds, and often used for decking screws into wood.

*NOTE* Many of these are or were trademarked/patented, and as such you will like encounter Posi-Square, Tri-Wing, XCD-Gasm, and a host of other custom names. Look them up and verify before "screwing around"!

RECAP I suspect Pozi (for precision) and Phillips (for cheap) are the most commonly employed and thus mixed up, but neither JIS, PH# nor PZ# should ever be mixed tool+screw as it will damage both. Remember to look for the "." in the corner of the "+" for JIS, the "X" overlaying the "+" for Pozi', and then go UP and DOWN sizes until you find the best fit. If a screw pointing up cant keep from falling off of a driver pointed up, something is wrong.


2. SCREW HEAD SHAPES
There's Button, Pan, Socket, Flush, Countersunk, and hybrids. I'd hazard all "decent" ones for skis are going to be flush (flat top, no dome nor "button") to avoid sticking up, and countersunk (conical underside) to self-center.

Remember the Phillips =/= Pozi' =/= JIS? Given TM, patents, and lawyers, The odds of all countersunk screws using the same cone-angle isn't likely. Both the screw and hole (or more likely, mounting plate) need to be the same cone angle, otherwise the screw will only make contact at the lip or at the root, versus distributing force along the full face.

EVEN if the cone angle is the same between say a Phillips and a Pozi', what you may find is the Cone Height (and thus the Screw Head Diameter) is different. If short, you're leaving wall on the mounting plate unused, and if long the head will stick up and not be flush. TEST THE SCREW FIRST by putting it through the plate, pull on the screw threads, and swing it around like a ball joint. If it swings from the side to center (or centered to side) and doesn't seem to settle in and "lock" when centered, it's not mating to a same-size cone. Try it with new plates and the screws provided, then take the plate and one screw and compare and test fit with other types.

If the threads, length, screw material, top (flush, or slight dome) and underside (countersunk vs. shouldered) are the same, some might explore going to a different tool interface like replacing a Phillips with a Pozidrive (for ZIF) or Allen (so you can check tightness in the backcountry with a small L-key).


3. SCREW THREAD TYPES

TIP! To avoid cross-threading a hole that has already been tapped (threaded), put the screw in then very lightly press down while turning it COUNTER-clockwise (ANTI-cw for you U.K. folk) until you feel the thread click and drop in a tiny amount. Then turn a full 360 degrees to see if it the screw pushes out until the rotates to the same spot. If it does, then start to screw in.

If you feel more than one "click", it might already be cross-threaded. Try turning it in VERY lightly on the strongest "click" and if you feel ANY resistance, stop, unscrew, and try the other. Go with the one that affords the least resistance, though resign yourself that it may be damaged enough already that it will need to be repaired before the assembly is ready for use.

METAL VS. WOOD
Metal, or more properly "machined thread" rely on the strength of the material (usually metal) to make up for the small teeth of the thread. If you're screwing into metal (e.g. an insert), the ability to dis-assemble and re-assemble is desired, this is what you're likely using. Their tips are typically blunt.

Wood screws have noticeably wider and deeper threads and end in a point.

Sheet metal screws (aka self-tapping) look like wood screw threads, but the point is often like a drill tip to bore through to make a hole for the threads to engage.

IMPERIAL / "INCH"
Starting around 1/4" and up, the diameters are in fractions of an inch. Below that you'll see #8, #10, etc. The thread count is threads per inch so 48 will be finer that 24.

METRIC
Nominally, screws are labeled by their thread-hole diameter so a "M6" screw will fit through a 6mm hole. The thread count is the distance between threads so a M8x1.25-20 fits in a 8mm hole with threads 1.25mm apart and 20mm long as measured from under the head.

COURSE VS. FINE, and GRADES
Stronger screws in ascending order are Grade 2, 5, 8 in Imperial, and 8.8, 10.9, 12.9 in Metric for the most part. What some notice is that "stronger" bolts use "finer" threads. This is due to the "root diameter". All bolts of a given size have the same thread outer diameter. Thus coarser threads go deeper, meaning the distance from the "root" (bottom of the thread-valley) on one side to the other is less than on fine. Thus if you filed off all the threads of a M8x1.5 and a M8x1.0 bolt, the remain shaft of the 1.5 would be skinnier, less metal, and easier to snap.

By contrast, coarse threads have more "face" engaging the hole's threads. This can be offset by engaging more fine threads (deeper hole) or engaging a harder substance (metal insert vs. wood fiber). An M6 insert will engage with more ski material than a M6 screw on it's own. Let INSERT OR NOT debate begin!


4. SCREW MATERIALS (METALS)
For anything of strength, a metal screw is going to be used. Consider how it will react with:
- the elements
- the mounting plate
- the ski

Common materials are zinc-plated steel, painted steel, stainless steel, while aluminum and titanium might be seen for the gram-bean-counters. Different metals hold on to their electrons with different strengths, thus if placed together (especially with a little water, salt, muck to help it along) the electrons migrate like in a battery, a very, very, very weak and slow battery.

Boaters (marine) and engines/transmission mechanics know all too well how things like aluminum castings with stainless steel screws can "cold weld" over time. Even if removal is possible, then cleaned, some material is lost and thus strength. Keep this in mind and consider preparing the surface(s) between two different metals before assembly, and coating afterward. Melting some wax in, smearing with some dielectric (silicone) grease, or even dabbing with paint once assembled can help both keep water out and prevent the "tool interface" (the "+" of the screw head) from corroding to the point of stripping when removal is tried.


5. CONCLUSION
This is a post on the internet, not a Doctorate of Philosophy thesis.
Do your homework to figure out what you have first where possible, including things like:
- metric or Imperial
- what the proper "driver" (e.g. type of screwdriver or bit-insert) and size is, DO NOT just use a "#2 Phillips" on e-v-e-r-y-t-h-i-n-g.
- what the proper torque is for both the fastener/screw AND for the material it's threading into
- anything else that could affect the fit, function, security, strength, and or longevity

With all the above variables, why hardware store fastener sections have dozens of cases upon racks upon bins upon drawers upon cubbies upon... should make more sense now. Take some time and get to know all the different types.

There are plenty of images, pages, schematics, and tables already on the internet that you should be able to find them based on the above. You should be able to find 1/4" hexagonal bits (usually side-stamped with PH2, PZ1, JIS3, T25, etc.) for any type of screw to insert in a 1/4" female socket tipped screwdriver, or use in conjunction with a 1/4" ratcheting torque wrench, if not as a stand-alone dedicated screwdriver.

[Stephen]

@TallGrass, Nice and well-written — I learned a few things.
Just for fun, do you have any insight into the NNN BC thing with mounting screw engaging plastic in binding, potential problems that can cause, and resolution?

(Screw can stop turning because fully tight in binding before binding is pulled tight to ski problem.)
viewtopic.php?f=21&t=5334

[TallGrass]

Just for fun, do you have any insight into the NNN BC thing with mounting screw engaging plastic in binding, potential problems that can cause, and resolution?

(Screw can stop turning because fully tight in binding before binding is pulled tight to ski problem.)
viewtopic.php?f=21&t=5334

@Stephen
The first thing I would check is the depth of the hole + the thickness of the plate, versus the length of the screw. That is, I'd suspect the hole is not deep enough, the screw is too long, or the hole hit the base.

If you don't have one, I highly recommend getting a electronic digital caliper. Metal are more durable and plastic less likely to scratch softer materials like top sheets.

The solution may be as simple as getting a different screw (short metrics are often 10mm, 12mm, 16mm...),
spinning a nut on it then grinding down the screw tip a few mm (whatever the gap is + 1mm for compression) brushing the end to deburr then backing the nut off to clear the starting threads,
or filing/grinding a few mm off the tip if it is a wood/plastic screw.

If you can take a photo of the screw from the side and from the top next to a metric ruler I might be able to tell you more. A photo of the hole in the ski and the binding plate(s) from the top would be nice too, as well as what if anything you put in the hole (e.g. epoxy, wood glue, marmot snot, ...).

[Stephen]

Hi @TallGrass.
I have not explained the situation clearly.
Maybe the post link below will help.
See picture and additional write up here:
https://telemarktalk.com/viewtopic.php? ... e0311a57a1

[TallGrass]

I have not explained the situation clearly.
Maybe the post link below will help.
See picture and additional write up here:
https://telemarktalk.com/viewtopic.php? ... e0311a57a1

@Stephen
I saw your link. What I can not tell is if the binding is rigid or wobbles when screwed down. If it is rigid (like it is on risers), and the edges supposed to fit flush, that could be due to:

1. The ski top being rounded. Hold a straight edge across the top and see if you can rock it at all.

2. The "well" on the bottom of the mount being lower than the edge (or the edge higher). This would be a major error on the manufacturer's part. One could use some wet sand paper, smooth side on top sheet, then stroke the base to sand off until flush.

3. It could ALSO be that you're missing an insert like a gasket that goes around the frame of the base plate. This would allow for a plate to seal against any imperfections or curve on a top sheet. Rubber could be used, yet I'd guess a softer plastic (harder than rubber, but more giving than base plate) like HDPE (milk jug) would be used. You could always DIY with a milk jug (clear, OJ bottle white, motor oil bottle black or blue), tracing around a base plate on it with a sharpie and dotting each screw hole, cutting it out and punching out the holes so the "wells" protrude through and only the edge makes contact, and use as many as needed to "shim" it up. I would definitely want the plate's force transmitted as broadly as possible to the ski.

4. To be fair, there are so many "fingers" involved in designing, manufacturing, and packing bindings, I would not be surprised if the CAD designer entered the hole size based on NOMINAL (e.g. 6.00 mm) versus ACTUAL which incorporates a % tolerance (e.g. 6.08mm), thus injection moldings end up "tight". Or even that some bean counter in the supply department order screws with a slightly different spec (less likely given screw uniformity and standardization). In injection moldings, there is also a split between the two halves of the mold that usually leaves a line on the side, unless they design the mold so it is at the edge (what Lego does on their bricks). If "edged", the the bottom of the screw holes could have some "flash" where plastic leaked between the mold halves and you'd want to clean that swarf out.

EDIT:
I see you've modified that post. The backyard fix is to insert a screw through the base plate hole and turn it until it strips the binding hole "clean" and repeat. You could use a "donor" screw, though it won't damage the metal screw threads biting into the ski if the plate is plastic. If the plate is metal, use a donor screw, ream it, or drill it. If the screws provided are Philips, use an equivalent screw with an Allen or Pozi head (and driver) instead. If you have a round file, that make work with a few passes but is easy to elongate the hole. A file with a slight taper that can be spun to sand it wider is more precise, but is not self-centering like a countersunk screw would be.

If the screw is threading into BOTH the plate and the ski (vs. just the ski), you are NOT getting the most clamping force to hold the plate against the topsheet.

Much of this stuff is so second nature for me to deduce in my hands, that it's a trick to think of all the possible variables that could be at play based off a informationally less rich block of text -- if a picture is worth a thousand words, what is actually being there worth?

[Stephen]

EDIT:
I see you've modified that post. The backyard fix is to insert a screw through the base plate hole and turn it until it strips the binding hole "clean" and repeat. You could use a "donor" screw, though it won't damage the metal screw threads biting into the ski if the plate is plastic. If the plate is metal, use a donor screw, ream it, or drill it.

If the screw is threading into BOTH the plate and the ski (vs. just the ski), you are NOT getting the most clamping force to hold the plate against the topsheet.

Hallelujah and praise the lord.
I have finally heard back what I have been saying.

The screw threads into both the binding AND ski.
My solution has been to do what you outlined: spin the screw in the hole to create clearance before installation.
However, I have recently heard this double engagement is by design.
I sometimes think I know better, but what if the binding is made this way for some reason?
I don’t know…
In every application I have used a screw or bolt, it clamps a fixture, for example, to a structure (has clearance as it passes through the fixture).
But again, maybe there is a reason for this to be different.
To allow for extreme temperature expansion and contractions, for only one possible example.
This is what I’m trying to get to the bottom of!

[TallGrass]

@Stephen

However, I have recently heard this double engagement is by design.

From a maker or a marmot?

But again, maybe there is a reason for this to be different.
To allow for extreme temperature expansion and contractions, for only one possible example.
This is what I’m trying to get to the bottom of!

Walking that through...
How much expansion (measured) is there going to be over say 3mm of a M6 screw's "root diameter" in a threaded vs. unthreaded plate?
Is the thread engagement length in, and the plate material strong enough, to resist stripping under load (skiing) under various forces and temperatures?
How much elongation of the screw is there when torqued?
How much side force is to be mitigated and transferred via the screw shaft versus baseplate (e.g. via countersunk hole), versus baseplate-topsheet interface?

For mass-produced
consumer-grade ski stuff
with consumer-grade tolerances
known to be often installed "by the owner,"
I think that level exact-itude is both R&D wa$teful and a liability lawyer-wise, same as you do not design owner-assembled kids bicycles to require a Ph.D. in structural mechanics.

For competition skis such as Olympic-quality where winners are separated by 0.01sec, sure, I can see higher, tighter tolerances and assembly precision at play.

Regardless, a good design has to a Fudge Factor because even Olympic skiers don't want a screw that will snap the second it reaches +8.4F, nor snaps when they take their skis inside a 65F building to tune them up. That could ruin a run, a career (failure, injury), and thereby brand reputation. Hence any new design should hit the test lab first for stress tests under varying conditions to sift out any weaknesses BEFORE it's used to attach to a human.

That's how I look at it. If one is so far down the tech rabbit hole they are separated from triggering neurotransmitters (seratonin, endorphins, etc. ya know, "fun") by moving across H20 in it's countless forms amid varying states, the rabbit ceases to jump.

[Stephen]

@TallGrass, well, maybe.
But I don’t like just sort waving my hands around and chalking things up to random shit.
No disrespect meant.
For me, it’s just not an end-point with any satisfaction.

There have been way too many words killed along the way here…

Satisfaction, man — I want SATISFACTION!

[GrimSurfer]

@Stephen

However, I have recently heard this double engagement is by design.

From a maker or a marmot?

But again, maybe there is a reason for this to be different.
To allow for extreme temperature expansion and contractions, for only one possible example.
This is what I’m trying to get to the bottom of!

Walking that through...
How much expansion (measured) is there going to be over say 3mm of a M6 screw's "root diameter" in a threaded vs. unthreaded plate?
Is the thread engagement length in, and the plate material strong enough, to resist stripping under load (skiing) under various forces and temperatures?
How much elongation of the screw is there when torqued?
How much side force is to be mitigated and transferred via the screw shaft versus baseplate (e.g. via countersunk hole), versus baseplate-topsheet interface?

For mass-produced
consumer-grade ski stuff
with consumer-grade tolerances
known to be often installed "by the owner,"
I think that level exact-itude is both R&D wa$teful and a liability lawyer-wise, same as you do not design owner-assembled kids bicycles to require a Ph.D. in structural mechanics.

For competition skis such as Olympic-quality where winners are separated by 0.01sec, sure, I can see higher, tighter tolerances and assembly precision at play.

Regardless, a good design has to a Fudge Factor because even Olympic skiers don't want a screw that will snap the second it reaches +8.4F, nor snaps when they take their skis inside a 65F building to tune them up. That could ruin a run, a career (failure, injury), and thereby brand reputation. Hence any new design should hit the test lab first for stress tests under varying conditions to sift out any weaknesses BEFORE it's used to attach to a human.

Agree 100% with this.

It is “good enough” and “easy enough” in most use cases. But it is not perfect by any means.

I can’t speak to what people are looking for in terms of satisfaction. Is it the comfort of thinking they’ve bought a NASA quality component for $80? Is it the delusion that things are as simple as the manufacturer says it will be?

Installers need to know exactly what they’re dealing with and have a good sense of the product’s strengths and weaknesses before blindly following a set of simply written instructions.