drill bit to binding mounting screw diameter ratio

The ultimate telemark knowledge base and encyclopedia. All you need to know about free-heel skiing. History, technical terms, glossary, how-to's and tips. Just the facts, no opinions. Your #1 place to start for everything tele.

Moderators: Teleia Organa, Han Solo

Post Reply
User avatar
Spiny Norman
Posts: 96
Joined: Sat Dec 08, 2018 12:34 pm

drill bit to binding mounting screw diameter ratio

Post by Spiny Norman » Wed Feb 15, 2023 2:05 pm

I'm about to mount some telemark and some AT bindings. I don't have mounting info for either.

Is there a generally accepted ratio bw the width of the mounting screw and the width of the drill bit to be used?

For instance, when i am putting decking on a metal pallet I use a bit that is 1/32" smaller than the shaft of the bolt. I can measure the screws with a caliper.

Thanks

User avatar
Stephen
Posts: 1293
Joined: Thu Aug 06, 2020 12:49 am
Location: PNW USA
Ski style: Aspirational Hack
Favorite Skis: Armada Tracer 118 (195), Gamme (210), Ingstad (205), Objective BC (178), Nordica Enforcer 94
Favorite boots: Alfa Guard Advance, Scarpa TX Pro
Occupation: Beyond
6’3” / 191cm — 172# / 78kg, size 47 / 30 mondo

Re: drill bit to binding mounting screw diameter ratio

Post by Stephen » Wed Feb 15, 2023 2:45 pm

The presence of carbon fiber or metal would make a difference.
Not a direct answer, but maybe this will help?
https://www.slidewright.com/measuring-f ... bits-taps/



User avatar
fledersau
Posts: 33
Joined: Fri Nov 11, 2022 5:25 pm
Location: Québec, QC, CAN / Grindelwald, CH
Ski style: BC XC/D ex. Telemark 75mm, Snowboardcross and Alpine Skier
Favorite Skis: Asnes Ingstad Waxless 195cm, Asnes Rabb 188cm, Madshus Panorama M62
Favorite boots: Rossignol XP12 and BC X7

Re: drill bit to binding mounting screw diameter ratio

Post by fledersau » Fri Feb 17, 2023 12:20 am

Hi, i work as a tech in a ski shop and i mount bindings all day long.
For AT and tele bindings for downhill usually you use 9 to 9.5mm length drill bits. For XC or BC XC bindings the length can go up to 15mm. check the length that the screw that goes out of the bottom of the binding.

For drill bit diameter, usually it's 3.5-3.6mm, but when there is a bigger carbon topsheet or a metal plate, it's 4.1mm and a tool to make a thread is best.



User avatar
Spiny Norman
Posts: 96
Joined: Sat Dec 08, 2018 12:34 pm

Re: drill bit to binding mounting screw diameter ratio

Post by Spiny Norman » Fri Feb 17, 2023 1:32 pm

Thanks



User avatar
Jurassien
Posts: 140
Joined: Tue May 10, 2022 12:12 pm
Location: Switzerland
Ski style: Nordic touring; Alpine touring
Favorite Skis: Too many!

Re: drill bit to binding mounting screw diameter ratio

Post by Jurassien » Fri Feb 17, 2023 3:08 pm

fledersau wrote:
Fri Feb 17, 2023 12:20 am
Hi, i work as a tech in a ski shop and i mount bindings all day long.
For AT and tele bindings for downhill usually you use 9 to 9.5mm length drill bits. For XC or BC XC bindings the length can go up to 15mm. check the length that the screw that goes out of the bottom of the binding.

For drill bit diameter, usually it's 3.5-3.6mm, but when there is a bigger carbon topsheet or a metal plate, it's 4.1mm and a tool to make a thread is best.
Perfect answer, to which I can only add that special drill-bits, with depth-stop, are available which are intended specifically for mounting ski-bindings:

https://www.tognar.com/mounting-drill-b ... -bindings/



User avatar
phoenix
Posts: 687
Joined: Mon Jan 02, 2017 6:44 pm
Location: Vermont
Ski style: Mostly backwoods touring and turning these days.
Favorite Skis: Currently, Objectives; K2 Waybacks, old school XCD-GT's.
Favorite boots: Alaska's, Excursions, T1's

Re: drill bit to binding mounting screw diameter ratio

Post by phoenix » Fri Feb 17, 2023 11:02 pm

It's worth it to get the proper bits from Tognar. Skis often have the recommended drill bit size printed on the top sheet, or you could call the company, if you're unsure.



Post Reply