Technical FAQs

Tie Rod Thread Lengths

How much thread length will I need on the tie rods I am ordering?

Unlike hex bolts, lag screws, and structural bolts, there is no standard thread length for tie rods.  A detailer or engineer may specify the thread length for tie rods, but it is not uncommon for the thread length to be left unspecified.  When thread lengths are not specified, Portland Bolt will determine the thread length... Read more

Thread Angle

What is the thread angle degree requirement for threaded rods?

Per ASME B1.1, threaded rods should be made at a 60 degree top angle.  This is a standard that is produced throughout the United States, however, in recent years, Chinese manufacturers have figured out a way to save on steel costs by manufacturing threaded rods with 45 or 50 degree angles.  This material does not... Read more

Stainless Grade 55 All Thread

Can I get stainless steel all thread rod in grade 55?

The reference to “Grade 55” is for getting a stainless steel all thread rod with a minimum yield strength of 55,000 psi.  There are currently no stainless steel specifications commonly stocked that will guarantee a 55,000 psi yield strength. The most commonly stocked grades of stainless all thread rod are A193, A320, and F593. The... Read more

Hot Rolled Round Bar Tolerances

What are the tolerances for round bar?

The bars we use to manufacture your bolts are rolled by the steel mill with standard tolerances for diameter, out of roundness, and straightness. ASTM A6 covers many of these tolerances, as well as the chemical and dimensional tolerances for other shapes and plates. Because round bar is what we primarily use, we will stick... Read more

Stainless Rust

Why are the hex heads of my stainless steel bolts developing rust?

There are two possible causes for this. First is that oxidation can occur due to contamination from equipment that is used to make other carbon steel products. This can leave some iron deposits that will rust over time. This is only aesthetic, but can be unsightly. The second possibility is that the bolts were not manufactured properly... Read more

Locking Tie Rod Assemblies

How do you lock a tie rod assembly in place?

The easiest way to lock a tie rod assembly in place is by including an extra nut that can be run up against either the clevis or the turnbuckle.  Once the nut has been jammed in place the assembly will be unable to move.  These pictures show that the nut has to be placed on... Read more

Turnbuckle Drawing

Turnbuckle Dimensions

How are turnbuckles measured?

A turnbuckle body is designated by the diameter of the rod threading into it and the length of the take-up inside the turnbuckle rather than the overall length. For example, a 1” x 6” turnbuckle body has an overall length of 8⅞”, but has an opening or “window” measuring 6”. Common sizes available are 6”,... Read more

Thread Runout

What is “thread runout” and what specifications cover it?

The thread runout portion of a bolt is where the threaded section transitions into the bolt shank.  This area exists beyond where the usable thread stops.  In other words, if you were to assemble a nut all the way onto a bolt, the nut will stop, but there will still be a small portion of... Read more

Pitch Diameter Bolts with Timber Connectors

Can I use reduced body bolts with shear plates and split rings?

Although ASME B18.2.1 allows for reduced body diameter bolts (where the unthreaded shank is equal to the pitch diameter of the threads), the American Wood Council does not.  In Section 13.1.3.3 of the 2015 National Design Specification for Wood Construction, it says: “Bolts used with split ring and shear plate connectors… shall have an unreduced... Read more

Class 1 vs 2 Stainless

Is there a way to visually distinguish the difference between a Class 1 and Class 2 stainless steel bolt?

Yes there is. A193 and A320 grades B8 and B8M are assumed to be Class 1 unless otherwise specified. Class 1 fasteners are carbide solution treated, while class 2 fasteners are carbide solution treated and strain hardened. The work hardening that occurs in the manufacturing of Class 2 fasteners increases their strength. Class 2 fasteners are differentiated... Read more