I started to replace all of the Torx bolts on my WG this afternoon and when I pulled the first one out of the triple tree I noticed that it was marked “HD8” Does anyone know if HD uses grade 8 bolts or if this is a meaningless marking? I would hate to use ungraded Allen bolts if I need a graded bolt and if it is a grade 8 then are graded Allen bolts available? I can’t say that I ever paid attention to grading whenever I bought Allens.

 

All hex socket head cap screws (commonly referred to as "Allen" bolts) are made of high strength alloys like 4140. They are actually superior in strength to outside hex head bolts that are Grade 8. Grade 8 bolts have six radial lines (clock marks) on top of the head, and are usually plated with zinc yellow dichromate. The HD8 that is on top of the torx bolts you are trying to replace is not a fastener industry marking, but more of an OEM (HD MoCo) identification. They are very likely Grade 8 or at least some kind of high strength fastener. One caution about Allen bolts. Make sure that whatever Allen bolts you use are plated. Zinc or zinc-yellow dichromate are the most common. A plain Black Allen bolt will rust immediatley. The high grade alloy used has a very high carbon content (essential for heat-treating) and will corrode rapidly. Plating keeps corrosion in check, but depending on the severity of the environment it is exposed to, over time corrosion will still come through the Zinc plating. Stainless steel bolts will not corrode, but are NOT high strength. It is not advisable to use a stainless steel fastener in an application where high strength is required. The torx bolts on your bike were designed for their application and it is probably best if you just leave them in there. But if you are going to replace them with Allens, rest assured that ALL are made of material of sufficient strength, but must have a plating or will corrode.

 

I could not say that any better MAC57.
I would go to a dealer and get replacement bolts for that item or contact a fastner co.

 

Mac57, Just the type of response I was looking for. Much appreciated. Thanks.

 

Stainless steel fasteners are available that are stronger than Grade 8. You just have to buy the right ones. I definitely wouldn't use an ungraded bolt for anything load bearing. Especially if it's holding the front end together!

http://www.alloyboltz.com/catalog/index.php

 

Your welcome. Glad to be of help.

 

CraigC, That's a great site! I've been selling commercial fasteners for 29 years and didn't even know about it. Great suggestion!

 

Really? I thought everybody knew about ARP, which looks to be the source of most of their fasteners. They have some grades of stainless that go over 250,000psi tensile strength.