Hobson UNC Square Neck Plough Bolt, 1/2 / 3-1/2

The Hobson UNC square neck plough bolt has a square neck under the head, which seats in a square hole to stop the bolt turning, and a UNC thread (Grade 8, plain). There are 26 items: 3/8", 7/16" and 1/2", in lengths from 1" to 4". Grade 8 is high tensile, and corresponds to metric class 10.9.

UNC means Unified National Coarse Thread and TPI means threads per inch. The square neck seats in a square hole, so check the hole as well as the bolt diameter and length.

Where this product is used

• Fitting through a square hole so the square neck stops the bolt turning while the nut is tightened
• Replacing a plough bolt of the same thread form, diameter and length

Features

• 26 items: 3/8", 7/16" and 1/2"
• Grade 8, plain
• Length 1" to 4"
• Sizes: 3/8", 7/16" and 1/2"

Key specifications

Choosing the right option

Choose the thread form first: the screw and the nut or tapped hole must match in thread form, diameter and pitch. Check the length against the thickness of the parts being joined, including the square neck.

Related items: Hobson UNC Square Neck Plough Bolt, Grade 9, Plain, 5/8" to 1-3/8" and Hobson UNC Stepped Plough Bolt, Grade 9, Plain, 5/8" x 2-3/4", Box of 100.