A good quality bolt is the lifeline of any project or equipment, if the bolting’s are of good quality they will give extra life to the application and where it is used. We have in house testing facility for all kinds destructive and non-destructive testing which are required for testing bolts and nuts. We also follow our own QAP or customers QAP.

Electronic Universal Testing Machine

•   Model : UTE 200
•   Make : FIE, India

Electronically controlled 200 Ton / 2000 KN load capacity, it is capable to check the ultimate tensile strength, yield strength, reduction in area ratio and give digital outputs for easy study of behaviour of materials, we also have a extensometer to check proof stress at 0.2% offset.

Yield Strength
The yield strength is the point at which plastic deformation occurs under stress. This is determined during testing over a measured gauge length via the use of devices known as extensometers. The devices may be either be mechanical clip on or video where non-contact is a limitation, e.g. elevated temperature testing.

Ultimate Tensile Strength (UTS)
The UTS is the maximum stress that a specimen is exposed to during testing. This may differ from the specimen's strength when breaking depending on if it is brittle, ductile or has properties of both. These material properties can change depending on environment, for example in extreme hot or cold conditions.

Ductility
Ductility relates to the elongation of a tensile test. The percentage of elongation is calculated by the maximum gage length divided by the original gage length. It is commonly described.

Tensile Specimen Preparation
Tensile test specimens are prepared in a variety of ways depending on the test specifications. The most commonly used specifications are BS EN ISO 6892-1 and ASTM E8M. Most specimens use either a round or square standard cross section with two shoulders and a reduced section gauge length in between. The shoulders allow the specimen to be gripped while the gauge length shows the deformation and failure in the elastic region as it is stretched under load. The reduced cross section gauge length of specific dimensions assists with accurate calculation of engineering stress via load over area calculation.

Types of Tension Testing

Other types of tension testing can include:

a )   Proof Test where a fixed load is applied to a structure and then removed before the structure enters service. This applied to mooring chains and introduces some permanent deformation and increases the strength.
b )   Pressure Test is applied to any equipment that will be under pressure. The level of pressure applied is more than normally experienced.

All high tensile bolts and nuts manufactured in our factory in India are required to be tested for their mechanical properties on a tensile testing machine, we ate Big Bolt Nut have the complete facility and equipment to perform Tensile testing on bolts, UTM machine, profile projector, hardness tester, mechanical testing on bolts and nuts.