Arch Bar Trucks

steamerdave · **Posted:** Thu Oct 29, 2009 1:48 am

Can anyone supply the ARA or MCB rules for column bolts for 50 ton trucks?

I am trying to find an off the shelf source for the 1&3/4 dia. x 26 inch long forged bolts.

The AAR general bolt spec M--125 addopted in 1944 lists the minimum tensile as 60KSI but this may not have included column bolts.

Loco112 · **Posted:** Thu Oct 29, 2009 3:01 am

What year of the regs were you looking for/attempting to meet?

steamerdave · **Posted:** Thu Oct 29, 2009 3:23 pm

I'm not sure exactly, Arch Bar trucks appear in the 1925 carbuilders cyclopedia but were outlawed for interchange in the 40's I think. So anything you find would be helpful.

I now have some quotes from a couple of suppliers, but they are custom forged of A307 material which is equivilent to a grade 2 bolt. That may be the actual material used which is what I am trying to find out.

SZuiderveen · **Posted:** Thu Oct 29, 2009 5:58 pm

1916 Master Car Builders' standard.

Steel spec. added 10/30/09 (copied from Google Books)

Steve

David Johnston · **Posted:** Thu Oct 29, 2009 10:48 pm

At the Western Railway Museum we have not replaced any column bolts, but we have replaced many box bolts. The bolts removed are usually stretched, worn or have hex heads. All the trucks we have worked on, either arch bar or with Andrews side frames, have stops cast into the various castings to engage square head bolts. These casting features do not porperly engage a hex head, and clearances make using wrenches diffcult, so the square head is necessary. Due to all the streched bolts we find we went to bolts meeting the requirements of SAE J429 grade 5.

I doubt you will find a square head grade five bolt of your exact dimension in stock any where. The bolts for WRM were made by United Steel and Fasteners of Itasca, Il., 630-250-0900. The make bolts for track frogs, so what you are looking for will be something they are familiar with.

S. Weaver · **Posted:** Fri Oct 30, 2009 12:55 pm

We put a lot of miles on our archbars. It is not uncommon to have the symptoms Mr. Johnston mentioned. We also have had to replace bolts due to corrosion or crankshafting (working). I would be hesitant to put anything less than a Grade 5 bolt in either a column or pedestal application. Fastenal has provided custom, Grade 5 hex and square head bolts for us. They aren't cheap and there is some wait time involved.