noob question-shield anchor bolts

what?

Hello,
maybe just confusing myself here... but...
Got some shield anchor bolts to hold a bike stand.(M10x108)
Bolt is 108mm, packet instructions say drill hole should be 65mm.
I dont get it, make a hole 65mm deep for a bolt that is 108?
Am I missing something really obvious here?

Calahonda52

what depth is the material u are bolting through?

what?

ta, its about 12 cm

Calahonda52

can you post a picture or link of the bolt

what?

this one here:
https://www.screwfix.ie/p/easyfix-shield-anchor-bolt-type-m10-x-108mm-5-pack/13317?_requestid=86767

The Continental Op

Drill the hole as deep as you like provided the anchor part of the system (everything bar the bolt washer and bolt head) fits in it. Ideally drill only as deep as needed. Don't think too many people would even bother reading the instructions apart from maybe to check the drill diameter needed.

Of more concern is drilling the hole the correct diameter. I've have found if the hole for that type of anchor is even slightly too big then it tends to be difficult to get them to start to grip.

what?

thanks, makes sense, having not done this before, decided to read instructions, hence confusion.
Again thanks

fiacha

The Continental Op wrote: »

Of more concern is drilling the hole the correct diameter. I've have found if the hole for that type of anchor is even slightly too big then it tends to be difficult to get them to start to grip.

If using an SDS drill I start with a bit a half size smaller (8mm bolt = 7.5mm drill) as I find the SDS makes a slightly oversized hole. I had the same issue with some concrete screws before changing bit size.

hesker

Given the max fixing depth is 50mm it’s likely they have specified the minimum drilling depth

The Continental Op

hesker wrote: »

Given the max fixing depth is 50mm it’s likely they have specified the minimum drilling depth

That sounded a good idea when I read it but when I thought about it a bit more. I'd never install one of those anchors with some of it in the fitting it was holding.

Without checking I'd take the max fixing depth to be the max depth of the material that length of screw in that anchor would hold, but the use of the word depth is slightly strange if it means thickness.