Wedge bolts' issue


Original Post
zibircut · · Unknown Hometown · Joined Mar 2013 · Points: 10

Folks, I have 10 mm wedge bolts from Fixe, and every once in a while I seem to find that the bolt gets wasted as the bolt gets stuck midway.

am I doing something wrong?

20 kN · · Hawaii · Joined Feb 2009 · Points: 1,348

Are you drilling the hole with a 10mm drill bit? Lots of people seem to like to use 3/8" bits for 10mm bolts, but you shouldent. A 10mm bolt is designed for a 10mm hole, not a 3/8" hole. My suggestion would be to use the remainder of your stock and then buy actual 3/8" bolts from Hilti or another reputable brand. The Hilti Kwik 3 series are great options. They probably cost less than the Fixe bolts too. You can find 10mm bits on eBay and Amazon from overseas fairly cheap (like $5 each).

Also on an unrelated note, if placing 12mm bolts you absolutely must use a 12mm bit. A 1/2" bit is not safe when paired with 12mm bolts because it creates too large of a hole (13mm roughly) and the expansion clip/ cone will run out of expansion travel allowing the bolt to pull at low loads. The 3/8" bit with 10mm bolt is less of a safety issue because in that case it creates too small of a hole (9.5mm) but it does make it hard to insert the bolt.

zibircut · · Unknown Hometown · Joined Mar 2013 · Points: 10

Sorry, the Fixe wedge bolts are 3/8th in size.  And I am using appropriate sized drill bit.

John Wilder · · Las Vegas, NV · Joined Feb 2004 · Points: 1,530

Happens to me too every once in a while with 5-pieces. I usually take that as a sign to change my bit.

Micah Klesick · · Vancouver, WA · Joined Aug 2013 · Points: 3,894
John Wilder wrote:

Happens to me too every once in a while with 5-pieces. I usually take that as a sign to change my bit.

This. 

I'm drilling basalt and after about 10-12 holes the bolt will often start to get tight. That's when I change bits. 

Pnelson · · Unknown Hometown · Joined Jan 2015 · Points: 70
Micah Klesick wrote:

This. 

I'm drilling basalt and after about 10-12 holes the bolt will often start to get tight. That's when I change bits. 

Yup, bit's getting dull.  I do find that sometimes as the bit gets dull, you can bevel the edges of the hole a little to cut down the chances of the bolt getting stuck midway.  But it's also time to get a new bit.

T Roper · · DC,VA,NM,UT,CT,MA · Joined Mar 2006 · Points: 860
John Wilder wrote:

Happens to me too every once in a while with 5-pieces. I usually take that as a sign to change my bit.

This and let the drill do the work and dont push too hard, you'll find the bits last longer, sometimes twice as long.

zibircut · · Unknown Hometown · Joined Mar 2013 · Points: 10

Thanks a lot folks!  Think I have been spoilt too much by the 5-piece Rawl bolts, that seem to last 50-60 bolts before I need to change the drill bit.

Jim Titt · · Germany · Joined Nov 2009 · Points: 490

As the bit wears run it in and out a few times in the hole which helps a lot, also change to a better bit manufacturer. Hilti are best but horribly expensive!

Also!!! Last month I had a long discussion with a customer who had loads of problems with 12mm bolts (in slate) where about a half of them  jammed going in. After a here and there about how to change them he tried my original suggestion and actually used a decent sized hammer which solved the problem.

nbrown · · western NC · Joined Nov 2007 · Points: 5,474
zibircut wrote:

Sorry, the Fixe wedge bolts are 3/8th in size.  And I am using appropriate sized drill bit.

From my experience the Fixe wedge bolts that are advertised as 3/8" are actually 10 mm in diameter. I've used them on and off for years and this has always been my experience. I just checked my (new) stock of them against my 3/8 hilti kb3s for comparison and can confirm that this is still the case. I know the threads are different but for a quick check try switching the nuts on the Fixe "3/8" with a Hilti 3/8 if you have one of each.

Although not ideal, if you are hand drilling with a new bit (especially in medium-hard rock) or you "ream out" the hole (as previously suggested) they will work okay with a 3/8 bit.

Guideline #1: Don't be a jerk.

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