Dane's FAQs

A490 vs F3125 Grade A490

What changes have occurred to the ASTM A490 specification since it was incorporated into the F3125 specification?

In December 2015, ASTM committee F16 approved the new F3125 standard, which combined six structural bolt standards, A325, A325M, A490, A490M, F1852, and F2280. The goal was to clean up inconsistencies within those various standards and combine them, so that future updates would be easier and less costly. The goal was not to drastically change... Read more

A325 vs F3125 Grade A325

What changes have occurred to the ASTM A325 specification since it was incorporated into the F3125 specification?

In December 2015, ASTM committee F16 approved the new F3125 standard, which combined six structural bolt standards, A325, A325M, A490, A490M, F1852, and F2280. The goal was to clean up inconsistencies within those various standards and combine them, so that future updates would be easier and less costly. The goal was not to drastically change... 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

Tightening Bolts by the Head

Can I tighten A325 and A490 structural bolts by turning the head of the bolt?

Yes. Per the RCSC Specification for Structural Joints Using High-Strength Bolts (2014), section 8.2, it says: “When it is impractical to turn the nut, pretensioning by turning the bolt head is permitted while the rotation of the nut is prevented, provided that the washer requirements in Section 6.2 are met”

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

Turn of Nut Method

What is the turn of the nut method, and does it apply to anchor bolts?

The turn of the nut method is a very popular and reasonably reliable method for tensioning (F3125) A325 and A490 structural bolts without the need for expensive torque wrenches or tension measuring devices. It is a simple guide that tells the user to rotate the nut a specified amount depending on the bolt length and... 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

Grade 7 vs Grade 7L

What is the difference between A194 grade 7 and grade 7L nuts?

A194 grade 7 nuts are commonly used nuts for both high temperature and low temperature applications, and is commonly paired with bolts made to either A193 or A320. When used in conjunction with A320 bolts in a low temperature application, or if specially requested, they are charpy tested to assure they will perform well in... 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

Extra Washers

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.