Certification and Testing FAQs

Certificate of Materials Origin (CMO)

Does Portland Bolt provide CMOs for state DOT projects?

Yes, Portland Bolt will provide CMO paperwork for DOT projects in the US. The purpose of a CMO is to document the origin of materials used on a construction project. A CMO is required under the Buy America Act and applies to all federally funded highway construction projects. A CMO is used to certify that all... Read more

J429 Strength Requirements

Why are larger grade 2 and grade 5 bolts less strong than smaller diameter bolts?

The reason is similar but different for the drop in strength of grade 2 and grade 5 fasteners. For J429 grade 2 fasteners, the drop is due to the manufacturing process. Small, mass produced cap screws are cold formed by drawing and forming wire. The wire, as it is cold formed, work hardens which increases... Read more

A325 Testing

Is rotational capacity testing required for A325 bolts?

Rotational capacity testing  a test “intended to evaluate the presence of lubricant, the efficiency of lubricant, and the compatibility of assemblies.” The test is intended primarily for galvanized fasteners, and fasteners that must be fully tensioned in structural applications. With A325 bolts now falling under the new F3125 specification, which covers high strength structural bolts,... Read more

Charpy Testing

What is Charpy Testing and what ASTM standards require it?

Charpy testing, or impact testing was developed in 1905 by Georges Charpy in order to determine the amount of energy absorbed by a material during fracture. It was noticed that as the temperature drops, the tensile and yield of steel increases, but the ductility drops, leading to brittle and sometimes catastrophic failures. A standard Charpy... Read more

SAE Grade Markings

What are the grade marking requirements for SAE rods or studs?

Answer: SAE J429 is a Society of Automotive Engineers specification for bolts covering “the mechanical and material requirements for inch-series steel bolts, screws, studs, sems1, and U-bolts used in automotive and related industries in sizes to 1-1/2 in inclusive.” From SAE J429 regarding studs: “The term ‘stud’ as referred to herein applied to a cylindrical... Read more

Proof Load for Large Nuts

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

ANSI B18.2.1

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

Proof vs. Yield Strength

What is proof strength of a bolt and how it is different from yield strength?

Proof strength, or proof load, is the full size equivalent of a yield test. Yield testing is typically only performed on machined specimens. In most fastener standards, full size testing is the preferred method, and the referee method if there is a discrepancy between the two test results. Because of the difficulty of getting reliable... Read more

Split lock washer drawing

Lock Washer Strengths

Are lock washers available in different strengths and what ASTM specification(s) cover them?

The term “lock washer” can include a huge variety of different products used in many different applications that often are very specific and can include many different grades, materials and purposes. When our customers refer to a lock washer, we assume they are referencing a “split lock washer” that is a generic lock washer that... Read more

Fastener Standards Organizations

What standards organizations and specifying committees cover the types of bolts and fasteners Portland Bolt manufactures?

Portland Bolt manufactures a wide range of bolts and fasteners to numerous standards set by many different organizations and specifying committees. There are many different organizations for fasteners, all of which have their own set of standards and guidelines for manufacturing. We, as estimators, are often asked what the acronyms for such organizations and committees... Read more