Screw Lengths for Threaded Inserts

[jondrums]

Enough people are using inserts now with various bindings, that I think its time to compile information in one place. Hopefully this becomes a central resource for screw lengths. I will maintain the master list and keep this post updated with all the latest information. Screw lengths are marked verified when someone has successfully mounted the bindings to inserts using those exact screws.



I'm using a google doc to keep everything in one place. Find a summary page here

Please post to the thread if you have or need information about working setups.

[jondrums]

Some information about how to measure screws:
*Flathead and Smallhead screws are measured as the total length of the screw, while Buttonhead screws are measured as the length of just the threads



*Fasteners should protrude 4mm MIN and 6mm MAX into a threaded insert
*To determine the idea fastener length, press an existing screw into the binding hole. Make sure it has bottomed out in its hole. Measure how far it protrudes below the base of the binding.

*Measure the screw itself as well. Subtract the protrusion length from the length of the screw. Add 5mm to that length. Find the closest size fastener that is within 1mm of that number. In this example, 13mm - 9mm + 5mm = 9mm. Either an 8mm or 10mm flathead would be appropriate for this binding.

[jondrums]

reserved reserved

[Knut]

Do you mind telling me, what exactly a smallhead is? I just know the precise german terms and when I do a google pic search, I get all kind of screwhead forms.

[jon gaper]

In cases where different length screws have been verified,is it best to use the longest ?

[thin cover]

so no button heads in the center holes on the new marker line up, Any particular reason for that?

[Alpinord]

Nice Jondrums. Thanks for posting and maintaining this.

A couple additions. The 5mm x 0.8mm machine screws means that for every revolution of the screw, the screw will move 0.8mm due to the fact that there is 0.8mm between threads. For the MIN 4mm, the screw needs to rotate 5 times. For MAX it takes 7.5 revolutions.

A variable that can be introduced is how deep you install the insert. All inserts should not be installed proud of the top sheet, at the highest, flush. If you install it deeper than flush, take that into account when measuring screws.

You can always grind or file a longer screw. Get extras 'just in case'. If a screw is too long and you use too much force, you can turn your insert into a spinner. This can also be a bummer if you install your binding while the epoxy is not cured and try to remove it. If in doubt, simply place a screw through the binding's base holes and screw on an insert from below to check revolutions and gap if too long.

EDIT: When you cut off or grind down a screw, often the end needs deburring and sanding to allow for smooth threading. One technique is to put one or two nuts onto the screw before you cut, grind or file the end. After the modification remove the nut(s) to 're-die cut' the screw end.

The new F10/F12s use the same (18) flathead alpine screws for all holes. I counted 6 revolutions (4.8mm) for a 10mm screw in the heel 'plate'. Measuring the depth of the top of the rear 'plate' to bottom of insert is 13mm. So 10mm MIN & 12mm MAX. (I'll revisit this later when I have more time to double check.)

[Knut]

Marker Jester Schizo/Demo: 10x 10mm flathead & 8x 8mm buttonhead (verified)

For duke/baron/tour f12 & onyx I can confirm your screw choice. I just prefer for the 5th hole at the old duke toes a 8mm buttonhead with a muff (is that the right term? anyway, it's an ISO 7380 MF -this type here: http://www.inox-schrauben.de/WebRoot...E/7380MF_m.jpg)

[TripleT]

Great resource!
But A little confused...is the google doc representative of the pre-selected screw kits on BindingFreedom.com?

For example, I got on the insert train before the BF ones were available. I was under the impression that the PL inserts required metric screws ~2mm shorter. At the time I posted this in another thread for what is required to mount Dynafit FT12 to PL inserts:
"2 M5x16 special flatheads, 8 M5x16 flatheads and 8 M5x12 flatheads ($7.20)
(http://www.tetongravity.com/forums/s...58#post3080558)

If PL inserts do require 2mm less screw length, then why does the google doc for BF inserts say this exact same thing for Dyna- vertical models?

Thanks

P.S. Jon, I assume the posi-drive head metric screws aren't gonna happen?

[Alpinord]

Marker Jester Schizo/Demo: 10x 10mm flathead & 8x 8mm buttonhead (verified)

For duke/baron/tour f12 & onyx I can confirm your screw choice. I just prefer for the 5th hole at the old duke toes a 8mm buttonhead with a muff (is that the right term? anyway, it's an ISO 7380 MF -this type here: http://www.inox-schrauben.de/WebRoot...E/7380MF_m.jpg)

How about a 10mm buttonhead and a washer (epoxied if desired)?

[jondrums]

Do you mind telling me, what exactly a smallhead is? I just know the precise german terms and when I do a google pic search, I get all kind of screwhead forms.

Knut- I've coined the name small-head, which is actually just a standard flathead screw whose diameter has been turned down. For some reason, a number of bindings use heads like this: example look toepieces. For now, these are only available on my website, or if you put a regular flathead in a lathe and turn down the head.

[jondrums]

But A little confused...is the google doc representative of the pre-selected screw kits on BindingFreedom.com?

Yes, all of the ones verified by "jondrums" are representative of the kits on bindingfreedom. At one point, QK had about 1mm less thread depth for a total of 5mm or so. The 16mm screws in the FT12 kit protrude about 4.5-5mm.

P.S. Jon, I assume the posi-drive head metric screws aren't gonna happen?

I need to figure out which are the most used screws because its a bit of an investment to tool them up in each length. Short story, they will happen.

[TripleT]

I need to figure out which are the most used screws because its a bit of an investment to tool them up in each length. Short story, they will happen.

Shouldn't hold my breath for mounting up a ski soon-ish?

[Knut]

How about a 10mm buttonhead and a washer (epoxied if desired)?

Should also work. Especially, as it's recommended to not tighten that one screw too much.

[Alpinord]

Should also work. Especially, as it's recommended to not tighten that one screw too much.

I just double checked this. I don't think it matters in the current F10s, anyway. All the screws are the same and seated in a countersunk hole. Flatheads are needed, not button or panheads and no washer. I just posted an image of an '09 Baron next to the new F10s here.

I'd say the (18), 10mm flatheads is correct in your chart, Jon.

[ExoticSkis]

I found this handy image describing different head types at McMaster's site:


Hopefully the names of the various heads are industry-standard...or at least McMaster-standard...

[Alpinord]

The Bolt Depot also has several good downloadable fastener resources. Their page that includes head styles is here.

Shoulder screws make for excellent insert installers.

[Alpinord]

For Silvretta 500 Easy Gos, the bases are 3mm thick and the countersink is 9mm diameter. 10mm screws with 10mm flat heads are a little proud of the base and work with 6 revolutions. 8mm screws with 10mm heads are a little shy. With 9mm or less diameter flatheads, the 8mm screws work with 5 revolutions.

McMaster socket flatheads have 10mm diameter heads. The philips are 9mm.

[Alpinord]

G3 Targas: 14mm is fine.

[dewam]

I just measured a Voile Switchback X2.

I had ordered 18mm M5 from jondrums because that is what Voile used for their insert skis, and found them to be too long. I had a set of 16mm M5 flatheads that K2 supplied with their insert skis and measured those in the binding.

16mm M5 Flathead fully seated protrudes 6mm.

Using jondrums formula: 16-6=10 +5= 15

[Angel]

I'll have to go back and measure. For new Look Pivot 18 and FKS 180, the four toe screws and first two heel screws are the same. The back two heal screws are a bit longer. I will get actual measurements up some time this week. I ordered them from Jon, so perhaps he can chime in on sizes.

[mobygrape]

so much win in this thread. I must have asked Jon several of these questions in private emails. Thanks everyone for sharing the info.

[jondrums]

First post is now up to date based on discussion so far. I decided to try putting a screen-capture image up for quick reference. I'll redo the screen cap when new information gets added to the doc.

[jondrums]

I just measured a Voile Switchback X2.
Using jondrums formula: 16-6=10 +5= 15

I'll keep it at 14mm for now, since that should still get 4mm of engagement. If someone else can confirm a mounted working setup with 16mm, I'll update it.

[jondrums]

New initiative:
I'd like help cataloging the various versions of look/rossi bindings. Can anyone suggest a good way to refer to the various versions? right now, I'm using
FKS geze 4 hole
FKS/FKX
FKS reissue

It appears that there are two versions of the reissue, perhaps it could be split into p18/FKS180 and p15/FKS150?