Hobson UNC Flat Head Socket Screw, Zinc, 3/8 x 1", Box of 100

This Hobson item is a UNC (Unified National Coarse) flat head socket screw, zinc finish. The size is 3/8" x 1" (diameter x length). Head style: FHCS, Flat Head (Countersunk) Cap Screw.

The head is tapered so that it sits flush in a countersunk hole. UNC means Unified National Coarse Thread and TPI means threads per inch. Supplied as a box of 100.

Where this product is used

• Fixing into countersunk holes so the head sits flush, as in jigs, fixtures and covers
• Fixture and tooling plates where the work face has to stay flat
• Replacing flat head (countersunk) socket screws of the same thread form, diameter and length
• Interior frames and equipment where the part is kept out of the weather

Features

• 1 item: 3/8" x 1"
• UNC thread, flat head socket screw
• Zinc finish
• Supplied as a box of 100
• Zinc plated finish, for indoor and sheltered locations

Key specifications

Choosing the right option

Choose the thread form first: the screw must match its nut or tapped hole in thread form, diameter and pitch. Sizes are nominal diameters in inches; compare the threads per inch with your thread.

Zinc plating suits workshops, enclosed machinery and interior fit-out. Because the electroplated coating is thin, it is generally unsuitable for outdoor exposure and does not meet treated-timber requirements (not suitable for treated pine). Keep zinc plated parts for the dry side of the job, and use hot dip galvanised or 316 stainless where moisture, weather or salt air are involved.

UNC is the coarse inch thread, the general-purpose choice; it only mates with UNC nuts and tapped holes of the same diameter. For load-critical, structural or lifting joints, confirm the fastener against the engineer's specification. Fasteners are not lifting rated unless marked.

Related socket screws: Hobson UNC Flat Head Socket Screw, Alloy Steel, Plain, #10-24 to 1", Hobson BSW Flat Head Socket Screw, Alloy Steel, Plain, 1/4" to 5/8" and Hobson UNF Countersunk Hex Socket Screw, Plain, 1/4" to 1/2".