Hobson BSG5ZF0250100 1/4" x 1" UNF Hex Set Screw, Grade 5, Zinc plated

The Hobson UNF hex set screw has a hex head and a UNF thread, and is fitted into a tapped hole or through a clearance hole with a nut (Grade 5, zinc plated). This page lists 6 items: 1/4", 5/16" and 3/8", in lengths from 1/2" to 1-1/2".

Hobson lists grade 5 as high tensile, and its class and grade chart pairs imperial grade 5 with metric class 8.8 (manufacturer-stated).

The Hobson acronym list defines UNF as Unified National Fine Thread and TPI as threads per inch. The table gives the threads per inch from the Hobson thread table, for the sizes it lists (manufacturer-stated).

Every item is supplied as a pack of 200.

Where this product is used

• Fitted into a tapped hole, or through a clearance hole with a nut and washer, to clamp parts together
• Replacing a hex head screw of the same thread form, diameter, pitch and length
• Machinery, equipment and fabrication work where a hex head screw is called for

Features

• 6 items: 1/4", 5/16" and 3/8"
• UNF thread, threads per inch shown in the table
• Grade 5, zinc plated
• Length 1/2" to 1-1/2"
• Minimum tensile strength by size from the Hobson guide, shown in the table (manufacturer-stated)
• Spanner size across flats from the Hobson chart, shown in the table (manufacturer-stated)

Common specifications

Key specifications

Selecting the right option

Choose the thread form first: the screw and the nut or tapped hole must match in thread form, diameter and pitch. Sizes are nominal diameters in inches; compare the threads per inch in the table with your nut or tapped hole. Length is measured from under the head to the end of the screw. The spanner size shown is the across-flats size for the diameter from the Hobson spanner chart, in the Grade 5 and 8 column (manufacturer-stated). Strength figures are the minimum tensile strengths for the class or grade and size range in the Hobson guide, which is a head-marking table, so treat them as the class or grade minimum and not a test result for the screw (manufacturer-stated). For a different strength level see Hobson UNC Hex Set Screw, Grade 8, Plain, 1/2" and 5/8".

Related products

Related items: Hobson UNF Hex Set Screw, Grade 8, Plain, 1/2" and 5/8", Hobson BSW Hex Set Screw, Grade 2, Mild Steel, Zinc Plated, 1/4" to 1/2" and Hobson BSW Hex Set Screw, Zinc Plated, 5/8" x 1-1/2" to 4".