Metallics RSB22 1/4-20 x 3/8 in. Round Head Combo Stove Bolt Screws with Hex Nut - Steel Zinc - Each

Nuts are included. Each Metallics RSB22 1/4-20 x 3/8 in. round head stove bolt ships with a hex machine screw nut, which is the nut style cut specifically for machine screw threads. You don't need to add nuts to the order to make up a complete fastener.

Not much. At 3/8 in. of overall length with 20 threads per inch, the RSB22 is sized for thin stock, think sheet metal enclosures, box covers, strap and clamp work, where you only need a few threads past the material for the hex nut. Stack much beyond light-gauge sheet and the nut runs out of thread; step up to a longer bolt in the same 1/4-20 series instead.

No. The RSB22 is not Buy American compliant and is not ARRA compliant, and country of origin is listed as multiple. For federally funded work carrying domestic sourcing requirements, you'll need a domestically manufactured fastener instead.

Either one. The RSB22 has a combo head, slotted and Phillips in the same recess, so a flat blade or a #4 Phillips driver both work. The Phillips recess runs 0.255 to 0.268 in. diameter at 0.147 in. deep; the slot is 0.064 to 0.075 in. wide and 0.082 to 0.109 in. deep. Handy on a panel job where you're already holding one screwdriver.

It stands proud. A round head is a raised bearing head, not a countersunk one: the RSB22 head measures 0.443 to 0.472 in. across and 0.16 to 0.175 in. tall, so it sits on the surface and spreads load over the hole. If you need the head below the surface, you want a flat head bolt in a countersunk hole, not this one.

The RSB22 is carbon steel with a zinc finish, made from AISI 1006 to 1022 stock. Zinc plating handles indoor and protected use well, which matches its intended electrical, plumbing, heating and air conditioning applications. For sustained wet exposure or corrosive environments, specify stainless rather than zinc plated steel.

Rated at 60,000 psi minimum tensile, with a hardness of Rockwell B70 to B100. That is standard commercial machine screw strength, fine for mounting boxes, straps, covers and brackets. It is not a structural bolt, so don't substitute it where a graded hex cap screw is specified.

Yes, it's built to ANSI B18.6.3, the dimensional standard for slotted and recessed head machine screws. That means the head size, recess and thread will interchange with any other B18.6.3 1/4-20 round head bolt already on the job.

They're sold in a 100 piece jar, which is the order minimum, and the pack type is listed as clamshell. Shipping weight on the pack is 1.58 lbs. Other sizes and quantities are available by request.

At 1/4 in. diameter and 3/8 in. long, this one falls outside tensile testing. Steel machine screws from No. 6 through 1/2 in. are exempt from tensile testing when shorter than either 1/2 in. or three times the nominal diameter, and the RSB22 at 3/8 in. is under that 1/2 in. threshold. Sizes that do require testing meet the 60,000 psi minimum.