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Bolts 5/16-18 X 2-1/2 Carriage Blt S (Jar 100)
Additional Notes
- Other sizes and quantities available by request
Manufacturer Resources
Product Specs
- Arra Compliant:
- N
- Buy American Compliant:
- No
- Dimensional Standard:
- ASME B18.5-1990
- Division:
- Electrical H1
- Fastener Head Type:
- Mushroom
- Fastener Head Width:
- 0.688 - 0.719 in.
- Fastener Height:
- 0.156 - 0.176
- Fastener Length:
- 2/1/02
- Fastener Width:
- 0.307 - 0.324
- Field Application:
- Electrical, Plumbing, Heating, Air Conditioning Industries
- Hardness:
- Rockwell B70-B100
- Language Code:
- EN
- Neurspe:
- https://ideadigitalasset.com/DAMRoot/Original/10035/11237_ID-SPE-v1-ID-SPE-v1-Carriage_Bolt_18-8_SS_and_316_SS.pdf
- Order Minimum Imperial:
- 100
- Order Minimum Uom Imperial:
- JR
- Outside Diameter:
- 0.298 - 0.324 IN
- Pack Type:
- Jar
- Product Group:
- Fasteners
- Product Height:
- 7.25 in
- Product Length:
- 4.5 in
- Product Weight:
- 2558 g
- Product Width:
- 114.3 MM
- Sub Division:
- Electrical-E H2
- Tensile Strength:
- 60000 psi minimum
- Thread Direction:
- Right Hand
- Thread Per Inch:
- 18
- Yield Strength:
- 36000 psi minimum
- Department:
- Electrical
- Product Subgroup:
- Bolts
- Product Type:
- Hexagonal Bolt
- Type2:
- Hexagonal Bolt
- Series:
- CB and JCB
- Product Finish:
- Zinc
- Product Details:
- Hexagonal Bolt
- Product Material:
- Steel
Metallics JCB21 – Frequently Asked Questions
1) What size carriage bolt is the Metallics JCB21, and how many come in a jar?
The JCB21 is a 5/16-18 x 2-1/2 inch carriage bolt, sold 100 to a jar. The 18 is threads per inch, right hand thread, so it takes a standard 5/16-18 nut. Minimum order is one 100-piece jar.
2) Will a 5/16 carriage bolt pull square in my strut or channel without spinning?
Yes, that is what the head geometry does. The JCB21 has a mushroom head measuring 0.688 to 0.719 inch across with a square neck under it; the square shoulder bites into the hole and keeps the bolt from turning while you tighten the nut from one side. Head height is 0.156 to 0.176 inch, so it sits nearly flush. Shank is 0.298 to 0.324 inch outside diameter, which drops into a standard 5/16 clearance hole.
3) What grade are these carriage bolts, and what load can they take?
Strength on the JCB21 is 60,000 psi minimum tensile and 36,000 psi minimum yield, with hardness in the Rockwell B70 to B100 range. That is low-carbon commercial grade, which is what most strut, conduit hanger, and equipment mounting work calls for. If your drawing specifies a Grade 5 or Grade 8 fastener for a structural or high-torque connection, this is not that bolt.
4) Will these pass a Buy American or ARRA requirement on a federal job?
No. The JCB21 is not Buy American compliant and is not ARRA compliant, and country of origin is listed as multiple. If your project has domestic sourcing language in the spec, you need a domestically produced carriage bolt instead.
5) Are these zinc plated steel carriage bolts okay for outdoor or wet locations?
The JCB21 is plain steel with a zinc finish. Zinc plating handles indoor and protected exterior work fine, but for sustained wet exposure, coastal air, or anything submerged, go to a stainless carriage bolt instead. Zinc will eventually bleed and corrode in those conditions.
6) Does the Metallics JCB21 carriage bolt meet a dimensional standard I can put on a submittal?
Yes. It is made to ASME B18.5-1990, the dimensional standard for round head bolts including carriage bolts. That covers head diameter, head height, square neck, and thread dimensions, so a 5/16-18 ordered from a different supplier to the same standard will interchange.
7) Are nuts and washers included with the JCB21 jar of 100?
No. The jar contains 100 carriage bolts only. Order 5/16-18 nuts separately, and flat washers if you want bearing under the nut; the mushroom head side does not take a washer since it seats flush against the work.
8) What trades actually use these Metallics carriage bolts?
Metallics lists the JCB21 for electrical, plumbing, heating, and air conditioning work. Typical uses are anchoring strut and channel, hanging equipment and ductwork supports, and bolting through wood or sheet steel where you can only get a wrench on one side, since the square neck locks the bolt against spinning.
How fast can I get the Metallics JCB21 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the
continental
U.S.
Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit,
reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Metallics JCB21 come with a warranty?
Absolutely. The Metallics JCB21 is backed by a manufacturer’s warranty.
For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Metallics JCB21?
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installation tips, and troubleshooting. Contact Us
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