Understanding Markings and Grades on Nuts and Bolts – Fasteners Plus

When it comes to nuts and bolts, there are many markings that you may come across. Common markers include letters, numbers, dashes, slashes, dots, and many more. The markings are an indication of the fastener's make, material, and dimension.
Why do fasteners have markings? Read more to learn about the different markings bolts, screws, and anchors have and how they can help you.

Grade 2 Hexagonal Head Bolt at Tractor Supply Co.

BSF Bolts

Understanding Markings and Grades on Nuts and Bolts – Fasteners Plus

Bolt head markings—what do the letters and symbols mean?

These hex bolts are among the strongest grade of fastener available in steel. These screws are yellow zinc plated and made from steel for durability.

1/4 in. x 1 in. Yellow Zinc Grade 8 Hex Bolt (5 per Bag)

FASTENERS, MEASUREMENTS AND CONVERSIONS

10 x 2 Deck Screws 18-8 Stainless Steel, Square Drive, Type 17

File:Bolt Nut Markings SAE and Metric.svg - Wikimedia Commons

Know Your Bolts Redux - Make

Fastener Marking Requirements - Portland Bolt