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Proof Load

Fastener Proof Load Testing

A proof load test consists of stressing the product with a specified load that the product must withstand without measurable permanent set (Method 1 – Length Measurement). The load that is used to stress the fastener is specific to the size, and grade/property class.

Test Methods – Material and Property Requirements

Fastener testing allows you to determine the mechanical properties of externally and internally threaded fasteners, washers, direct tension indicators, and rivets. Testing may consist of a machined specimen or a full-size product. The type of fastener testing that will be described below applies to a full-size product testing. Fastener testing is not applicable to all. The head design, shank thickness, and product length can determine if the testing is required of the product.

ASTM F606/F606MStandard Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets
ISO 898-1Mechanical properties of fasteners made of carbon steel and alloy steel — Part 1: Bolts, screws and studs with specified property classes — Coarse thread and fine pitch thread
ISO 898-2Fasteners — Mechanical properties of fasteners made of carbon steel and alloy steel — Part 2: Nuts with specified property classes
SAE J995Mechanical and Material Requirements for Steel Nuts
SAE J429Mechanical and Quality Requirements for Externally Threaded Fasteners
SAE J1199Mechanical and Material Requirements for Metric Externally Threaded Steel Fasteners(STABILIZED Feb 2013)