Apr 10, 2021 · Screw and bolt head markings identify the manufacturer of the fastener and the standard to which the fastener was made. Below, we’ll explore both of those concepts, then connect them together with a few examples.

Jun 9, 2022 · The SAE J429 standard has specific requirements for bolts, screws, studs, sems, and U-bolts up to 1-1/2" in diameter. Bolts meeting SAE J429 standards have radial lines engraved on the bolt head. Grade 2, 5, and 8 are the most common grades of fasteners according to the Society of Automotive Engineers standard.

When you are dealing with inch-size fasteners, commercially sold in the U.S., there are three main standards organizations that specify the material, hardness, strength level, and the head marking requirements for steel and alloy steel fasten-ers. Those standards organizations are:

Oct 24, 2014 · The lines on the head of a bolt indicate its grade. SAE J429 (Society of Automotive Engineers) bolts have radial lines, whereas ASTM (American Society for Testing and Materials) uses a combination of letters and numbers to indicate the grade.

These charts helps to identify the grades of bolts using the identification marks on the bolt's head along with the strength and hardness of common grade bolts. Please note the bolt heads may also include the manufacturer's identification stamp, especially with high strength bolts.

Many fasteners (screws, etc.), especially smaller sizes, are typically not graded—their strength isn't specified. Larger sizes and those for specialized purposes, though, are made to meet certain strength requirements. Inch fasteners—those commonly used in North America—will have a grade or ASTM rating.

Nov 9, 2024 · The lines on a screw indicate its grade, which corresponds to its tensile strength. For example, three radial lines indicate Grade 5, which has a minimum tensile strength of 120 ksi for diameters of 1/4–1" and 105 ksi for diameters of 1–1 1/2".

When it comes to replacing a hex head cap screw, do you know how to determine the grade of the cap screw and what that “grade” actually means? This guide is designed to show you how to quickly and easily identify the grade of any hex cap screw and understand the meaning and uses for each grade and material.

Jan 24, 2021 · Have you ever looked at the head of a bolt and wondered what the markings mean? Maybe there's a series of letters and numbers, maybe just a few lines. The markings can indicate who manufactured the bolt. This will vary from manufacturer to manufacturer, but is usually one, two or three characters.

Here are the markings that indicate Grade 2, Grade 5, Grade 8 & Structural Bolts. Metric class 8.8 & 10.9 also.