Set Bolt

whats the difference between a ’set screw’ and a ‘bolt’?

Set screws do not have a head and are used to secure two or more components with no surficial protrusion. They act in shear, in that the screw is working to prevent the items from slipping longitudinally apart.

A bold has a protruding head and nut hich provide clamping force if tensioned and act in tension (clamping) and shear (preventing slipping of the fastened items).

Hope that helps.

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Bolt Distinguishing Charateristics

Bolt Distinguishing Characteristics

The Difference Between A Bolt And A Set Screw:

The Bolt: The Bolt is characterised as with out a full thread (i.e the thread does not reach the head), this part is known as the Shank. Bolts are generally not available in the shortest lengths as there is no room for the shank, and typically you will receive a Set Screw in place of a Bolt. The Bolt allows for movement.

The Set Screw: The Set Screw is characterised as with a full thread (i.e the thread reaches the head). Used to prevent relative motion (no movement).

Metric and Imperial Bolt Markings:

Metric Bolts have numbers marked on their heads to distinguish their grade. The most common being 4.8, 5.8, 8.8, 10.9, but there are a lot more grades. The manufactures markings can also be found on the head. 

           Class 4.8

Class 5.8

Class 8.8

Class 10.9

The numbers on the bolt represent the bolts Tensile Ultimate Strength (before the point) and the bolts Tensile Yield Strength (after the point). Please visit http://www.ngoye.com for a more descriptive breakdown and calculation of Bolt Tensile Stength. 

Imperial Bolts have line marking on their head to distinguish their grade, the most common grades being Grade 2, Grade 5 and Grade 8. There are more grades but are not as commonly used.

The bolts are marked on their head’s with diagonal lines to show what bolt grade they are:

Grade 2 Imperial Bolt is a standard hardware grade steel. This is the most common grade of steel fastener and is the least expensive. Grade 2 bolts have no head markings but a manufacture’s marking may be present.

Grade 5 Imperial Bolt’s are hardened to increase strength. Grade 5 bolts have 3 evenly spaced lines on the head

Grade 8 Imperial Bolt have been hardened more than grade 5 bolt’s, thus they are stronger and are used in more demanding applications. Grade 8 Bolts have 6 evenly spaced radial lines on the head

 For a fully illustrated description please visit http://www.ngoye.com and look under Engineering Supplies – Technical Information

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Bolt holds off Powell to win Paris Diamond League 100
SAINT-DENIS, France (AP) Olympic and world champion Usain Bolt recovered from a poor start to win the 100 meters at the Paris Diamond League meet in 9.84 seconds on Friday night. Bolt set a new meet record and beat Jamaican compatriots Asafa Powell, who finished second in 9.91, and Yohan Blake in third at 9.95.