Metallics RSB105 1/4-20 x 2-1/2 in. Round Head Combo Stove Bolt Screws with Hex Nut - Steel Zinc - Each

Each Metallics RSB105 1/4-20 x 2-1/2 inch round head stove bolt ships with a hex machine screw nut, so no separate nut purchase is needed. The nut is the machine screw style, sized specifically for machine screw threads rather than a standard structural hex nut.

Yes. It is a 1/4-20 right hand thread, 20 threads per inch, cut to ANSI B18.6.3, so it mates with any standard 1/4-20 tapped hole, channel nut, or coupling of the same class.

No. The RSB105 is not Buy American compliant and is not ARRA compliant, with multiple countries of origin. On a federally funded project with domestic sourcing requirements, you will need a domestically produced fastener instead.

The RSB105 head takes a #4 Phillips driver, or a flat blade for the slot. The recess is 0.255 to 0.268 inch across and 0.147 inch deep; the slot is 0.064 to 0.075 inch wide and 0.082 to 0.109 inch deep. A screw gun with a #4 Phillips bit and a medium flat tip both work on the same fastener, which is handy when you are reaching into a box and only have one bit on you.

With 2-1/2 inches of overall bolt length, you lose the nut height and a couple of threads of engagement, so the practical grip is what is left of that length once your nut and washer stack is accounted for. The round head itself sits 0.16 to 0.175 inch above the surface and spans 0.443 to 0.472 inch, so it covers an oversized 1/4 inch hole but will not sit flush. If you need flush, use a flat head machine screw instead.

The RSB105 is zinc plated carbon steel (AISI 1006 to 1022). Zinc plating handles indoor and dry or lightly damp locations well, but it is sacrificial and will eventually corrode in wet exterior, coastal, or chemically aggressive spots. For sustained wet exposure, specify stainless rather than zinc plated steel.

Steel machine screws from #6 through 1/2 inch diameter are subject to tensile testing when they are longer than either 1/2 inch or 3D, where D is the nominal diameter in inches. At 1/4-20 by 2-1/2 inches, the RSB105 is well past that threshold, so it falls in the tested size range and must meet the 60,000 psi minimum tensile load requirement.

They are sold in a 100 piece pack, with a minimum order of one jar of 100. Packaging is a clamshell or square plastic jar depending on the run. Other sizes and quantities are available by request.