Newest FAQs

Are there restrictions on using extra washers to accomodate tightening a nut onto a bolt that may be a bit too long and the nut is running out of thread?

Per the RCSC section 16.2-12, multiple washers are permitted under the nut in order to resolve this problem.

What is the proof load rating for a large diameter (2-1/2”+) nut?

Nuts that are over 2-1/2” diameter do not require a proof load test because most testing equipment in the industry is not large enough to test them effectively. In these cases, a hardness test is an acceptable alternative, unless a proof load test is specifically required by the buyer. Nuts this large would require in... Read more

What is the proper tension for an anchor bolt, headed bolt, stainless steel bolt or bent bolt?

Only structural steel bolts have an associated tension recommendation. The desired tension on a structural bolt is achieved by using a calibrated torque wrench and a Skidmore-Wilhelm load indicating device to tighten the nut with torque indicated by a verified bolt torque chart. ASTM does not have any recommendations in place for the proper tension... Read more

What is the load rating for a coupling nut or sleeve nut?

There are no documented standards for load ratings of coupling nuts or sleeve nuts. These types of connections are not specified for any uses for which load rating would be required. If a connection is used to suspend or tension a load, which is achieved with products like tie-rod assemblies, then the connection products have... Read more

Hex Coupling Nut
Can I use a mechanically galvanized nut with a hot-dip or electroplate galvanized bolt (or vice versa)?

No, mixing and matching different types of galvanized products is not advised. From ASTM A563/A307/A354 and F1554: “4.7.4 When no preference is specified, the supplier may furnish either a hot-dip zinc coating in accordance with Specification F2329, or a mechanically deposited zinc coating in accordance with Specification B695, Class 55. Threaded components (bolts and nuts)... Read more

How is G90 galvanized steel different from F2329 (or A153) hot dip galvanized steel?

Both are produced via the hot dip process, but with slightly different processing steps. G90 is a coating grade within the steel sheet specification ASTM A653, and is produced by uncoiling steel coils and running it at high speed through the pickling process and molten zinc before it passes through an air curtain, which creates... Read more

Can ASTM A490 heavy hex structural bolts be fully threaded?

2015 Update: Yes, ASTM A490 bolts can now be fully threaded. There is a supplemental provision in the F3125 specification that allows the bolt to be fully threaded as long as it is stamped with an “S”. The A490 specification starts at ½” diameter and stops at 1-1/2” diameter, and each diameter has its own specific thread length... Read more

What are the product marking requirements for bolts?

Headed bolts are required to be stamped on top of the head, while most rods and some bent bolts are required to be stamped on one end. This Fastener Identification Markings Chart shows the various marking requirements for most common grades of ASTM and SAE fasteners. Headed Bolts ASTM specifications require a manufacturer’s identification and... Read more

B7 Hex Head Bolt
What is ANSI B18.2.1?

Often times, ANSI (American National Standards Institute) or ASME (American Society of Mechanical Engineers)  B18.2.1 will show up on a drawing, some certification documents, and even our website . This number simply refers to dimensional standards for a variety of common bolts, such as hex bolts, heavy hex head bolts, and square head bolts. Most... Read more

Does ASTM F1554 require headed anchor bolts to be stamped on the head with the fastener’s grade symbol and manufacturer’s logo?

Stamping the heads of F1554 anchor bolts is not required per the ASTM Specification, but Portland Bolt chooses to do so to provide a secondary identification. Product Marking ASTM F1554 anchor bolts are marked on the threaded end that projects from the concrete with a designating color code, as is required by the specification.  Marking... Read more

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