Home » Healing Arts » What is the difference between a325 and Grade 8 bolts?

For structural bolting projects, strength is everything. There are more similarities than variations when you compare ASTM A325 and Grade 8 bolts. A325 bolts are usually made of medium-carbon steels and SAE grade 8 bolts are made of a medium-carbon steel alloy (although they can be of an alloy). Bolts of grade 8 are much stronger than A325 bolts. ASTM A490 is an ASTM specification of grade 8 with equivalent force properties.

ASTM A325 Fasteners covers concrete bolts of high strength required for structural steel ties. A325s have a full body diameter and have a heavy hex head and are usually short in total length as they link steel to steel. A325 is unique not only to chemical and mechanical specifications, but also to the configuration that can be tolerated in relation to other ASTM grades. ASTM A325 Bolts is any kind of steel to which, purposely applied to one or more elements, a desirable physical property or characteristic is made apart from carbon. The ASTM A325 Carbon Steel Bolts are brittle at a certain temperature range.

Grade 5 While the chemical or physical forces and properties of both bolts are nearly similar, there are many variations between them. The rating criteria for Grade 5 falls under the Automotive Engineering Company (SAE), while the A325 falls under the ASTM requirement. In heavy-duty building projects ASTM A325 bolts are more widely used for use by technicians for structural steel ties, although in OEM-type applications SAE Grade 5 bolts are more common


Grade Nominal Size Proof Load Min (ksi) Yield Strength Min (ksi) Tensile Strength Min (ksi) Rockwell Hardness Min Rockwell Hardness Max
ASTM A325-1 1/2″ – 1″ 85 92 120 C24 C35
1-1/8″ – 1-1/2″ 74 81 105 C19 C31
SAE J429 Grade 8 1/4″ – 1-1/2″ 120 130 150 C33 C39


Finally, for each type of bolt that thread lengths are different. In Grade 8 Bolts, with a bolt shorter than or equal to 6 inches the normal thread length is two times the diameter or .25 inches for a bolt. The Normal Length is twice the bolt’s diameter plus .5 inches for bolt longer than 6 inches in diameter. For A325 bolts, some lengths exist, but usually they are much shorter than most other bolt grades.These types of pins have been engineered to tighten close to their evidence strength to produce considerable pull voltage. The norm notes that the tensile strength must be tightened to at least 70%. These bolts use the same material as their traditional cousins, however, the thicker and broader head is available to help distribute the load. The ASTM F568 M for metric bolts. Sometimes known as strong hex geometries, this modified geometry. ASTM A325 bolt is equivalent to the ASTM F568 M Category 8.8 bolt.

The ASTM A325 is the standards for heavy hex bolts in heat treated steel with a minimum of 120/105 ksi tensile strength. Two classes, type 1 and type 3, of A325 bolts from Glaser and Associates, give numerous mechanical and chemical properties for particular applications. If you have no magnet, you can still identify Grade 8 bolts by brushing the bolt head using a cord brush and count the radial lines. Bolt marks are not available.  On Grade 8 bolts there are six radial lines. Under the head, the length is measured. Various bolt grades consist of various metal alloys which have varying mechanical properties. Grade 8 bolts consist of medium carbon steel quenched and tempered. The bolts, which are made of non-temperate carbon steel, are almost two times as strong as grade 2.

Published at: Recent Health Articleshttp://recenthealtharticles.org

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