Best Flange Nuts and Bolts Assortments for Metric and Inch Projects
The best flange nuts and bolts kit depends on your thread system, material needs, and required size range. For inch fasteners, the BoltsandNuts.com Grade 8 set is the relevant option. For metric work, Mr. Pen and Besitu offer compact assortments, DIVANC lists stainless steel hardware, and RC Lelut provides the broadest size range. Compare the specifications below and match the fasteners to your equipment before buying.
| Assortment | Best For | Key Difference |
|---|---|---|
| BoltsandNuts.com Grade 8 | Inch-size projects | Yellow-zinc Grade 8 bolts and locking nuts |
| Mr. Pen 272-Piece | Metric general-purpose repairs | M6, M8, and M10 hardware with washers |
| Besitu 280-Piece | Metric projects needing listed Class 10.9 hardware | Black-finish bolts and labeled storage |
| DIVANC 300-Piece | Metric projects prioritizing stainless steel | 304 stainless steel hardware |
| RC Lelut 820-Piece | Shops needing more sizes and quantities | M6 through M12 sizes and longer bolts |
BoltsandNuts.com Grade 8 Inch Assortment
This assortment is best for buyers who need inch-size Grade 8 flange fasteners rather than metric hardware. The listed features describe yellow-zinc-finished Grade 8 hex flange bolts paired with matching Grade 8 top-lock flange nuts. That makes it a practical choice when a project calls for this fastener style and grade.
Why it was selected: It is the only listed kit specified as inch-size hardware, and it includes locking flange nuts. Check before buying: The product name says 352 pieces, while its feature description says 420 pieces. Confirm the current package count and included sizes in the listing before relying on a quantity.
Mr. Pen 272-Piece Metric Flange Kit
Choose this kit for common metric repairs requiring M6, M8, or M10 flange hardware. It contains 272 pieces, including flange hex-head bolts, nuts, washers, and lock washers. The listed bolt lengths range from 12 mm to 30 mm, and the hardware is identified as Grade 10.9 medium-carbon alloy steel.
Best for: Buyers who want a compact assortment covering three common metric diameters and several shorter lengths. It is a more focused option than the larger RC Lelut kit. Limitation: The listed range does not include M12 hardware or bolts longer than 30 mm, so check your fastener requirements first.
Besitu 280-Piece Black Metric Assortment
Besitu is best for metric buyers who want specified M6, M8, and M10 sizes with a black galvanized finish. The 280-piece kit includes bolts, nuts, and washers. Its listed lengths cover M6 bolts from 12 to 30 mm, M8 from 16 to 30 mm, and M10 at 30 mm. The product information identifies the bolts as 10.9-grade alloy steel.
Why it was selected: Its size chart and labeled storage bins can help users sort the included fasteners, while the stated grade provides a clear specification to compare. Limitation: The listed M10 selection is limited to 30 mm, and this is a metric kit, not an inch assortment.
DIVANC 300-Piece Stainless Metric Kit
This kit is best for buyers prioritizing stainless steel in a metric assortment. The product description specifies 304 stainless steel bolts, flange lock nuts, and washers, with M6, M8, and M10 diameters. Listed bolt lengths run from 12 mm to 30 mm, with M10 listed at 30 mm. Its silver finish is visually distinct from the black and yellow-finish options.
Why it was selected: It offers a stainless-steel alternative for projects where material and corrosion resistance are important considerations. Limitation: The listing does not provide a strength grade comparable to the Grade 10.9 claims on some other kits. Do not assume it suits a high-load application without checking the required specifications.
RC Lelut 820-Piece Wide-Range Kit
For a workshop that needs more size options and higher piece counts, RC Lelut is the broadest listed assortment. It includes M6, M8, M10, and M12 fasteners, with lengths from 16 mm to 50 mm depending on diameter. The kit description also lists flat washers and lock washers. Its flanged design is described as distributing load over a wider surface.
Best for: Buyers handling varied repairs who want M12 options and longer bolts alongside smaller metric sizes. Limitation: The feature list does not state a steel grade or specific material, so confirm those details if your application has defined strength or corrosion requirements.
Buying Guide: How To Choose Flange Nuts And Bolts
Do you need metric or inch fasteners?
Start by matching the thread system and size used by the equipment. Metric kits in this selection include M6, M8, and M10; the widest-range option also lists M12. The BoltsandNuts.com kit is described as inch-size. Do not substitute a similar-looking diameter or pitch: the threads must match the mating part.
Which bolt length and grade should you check?
Measure the required bolt length and compare it with the assortment list. A kit with many pieces may still omit the exact length you need. Where strength matters, verify the stated grade against the equipment or project requirements. The supplied descriptions identify Grade 8 for the inch assortment and Grade 10.9 for the Mr. Pen and Besitu kits; not every listing provides a grade.
When does material or finish matter?
Choose hardware based on the environment and application requirements. DIVANC specifies 304 stainless steel, while other kits list yellow or black finishes. A finish or material description alone does not establish that a fastener is suitable for every outdoor, corrosive, hot, or high-load use. Check the manufacturer’s requirements and the full product specifications.
Do flange bolts need washers?
A flange provides a wider bearing surface than a standard hex head, but the correct washer arrangement depends on the joint design. Several kits include washers and lock washers; others emphasize locking flange nuts. Confirm that the included components match your assembly instead of assuming all kits contain the same hardware.
Frequently Asked Questions
What is a flange bolt?
A flange bolt has a widened flange beneath its head. The flange provides a broader bearing surface than a standard hex head.
What is a locking flange nut?
A locking flange nut is designed to resist loosening compared with a standard nut. The exact locking feature varies, so review the product description.
Can I use a metric bolt in an inch-threaded hole?
No. Metric and inch threads are different systems and should not be treated as interchangeable. Match diameter and thread pitch to the mating part.
Which kit has the widest listed size range?
The RC Lelut assortment lists M6, M8, M10, and M12 sizes and lengths up to 50 mm for some sizes.
Which listed kit is stainless steel?
The DIVANC assortment is described as 304 stainless steel and includes metric bolts, flange lock nuts, and washers.