Hex Bolts
Manufacturer
India · Mumbai
Anatomy of a Standard Hex Bolt — The Deliberate Baseline
A standard hex bolt is, by design, the simplest possible answer to threaded fastening: a hexagonal head for universal wrench and socket compatibility, a straight shank, and a plain thread with no distortion, insert, or special drive geometry of any kind. Six flats give a wrench or socket 60° of engagement rotation and near-universal tool compatibility — the same six-sided drive shape used across almost every hex fastener made worldwide.
Everything about this design is intentionally unremarkable. There is no special head form because a standard hex head, driven with an ordinary wrench, is entirely sufficient for the vast majority of fastening needs. There is no special shank feature because most joints simply need a straight, threaded shank clamping two members together with a nut or into a tapped hole. There is no special material or finish beyond what the application’s load and environment require.
This is precisely why the standard hex bolt is the correct default choice for the overwhelming majority of applications — general machinery assembly, structural connections, equipment fabrication, and countless other uses where no specific complication exists to justify departing from the simplest, cheapest, most universally compatible option. Every specialty bolt we manufacture — headless, socket drive, square neck, dual-thread, or otherwise — exists because a specific application has a specific requirement this baseline doesn’t address. Knowing which requirement you have is the fastest way to the right product, covered in the section immediately below.
Why Standard Hex Bolts — Simplicity Is a Genuine Advantage
Universal Tooling Compatibility
Every wrench, socket, and spanner made for hex fasteners fits a standard hex bolt — no special tooling, no dedicated sockets, and no risk of the tool-mismatch issues that specialty drive geometries can carry.
Available in Full or Partial Thread
Choosing between full thread (DIN 933) and partial thread (DIN 931) lets the same basic bolt form suit either a thin clamped joint needing maximum engagement, or a thicker joint needing a smooth, unthreaded shear section — covered in detail below.
Lowest Cost, Simplest Manufacture
With no special head form, insert, or shank feature to machine, a standard hex bolt is the most economical bolt to produce at volume — the correct default wherever no specific complication justifies paying for additional features.
No Application-Specific Limitation
Unlike a headless stud bolt’s two-nut installation requirement or a socket head bolt’s internal-hex tooling need, a plain hex bolt carries no feature-related installation limitation at all — its performance envelope is defined purely by the base metal grade.
When to Deviate From the Standard Hex Bolt
Every specialty bolt in our range solves one specific problem the plain hex bolt doesn’t address. Find your actual requirement below and go straight to the page that solves it.
Stud Bolts
No head, two nuts — the stud itself never rotates, protecting gasket faces on flange connections.
View Stud Bolts →Heavy Hex Bolts
Larger head and across-flats per ASTM A325/A490 — the standard for slip-critical and bearing-type structural joints.
View Heavy Hex Bolts →Socket Head Bolts
Internal hex drive needs zero swing clearance — the compact head sits flush inside a matching counterbore.
View Socket Head Bolts →Allen Bolts
Same part as a socket head bolt — this page focuses on hex key sizing for everyday consumer and DIY use.
View Allen Bolts →U-Bolts
Headless, bent into a U-shape, encircling a pipe or rod rather than clamping down against a single face.
View U-Bolts →Carriage Bolts
A square neck self-forms its own seat in a wood pilot hole, resisting rotation with no second tool needed.
View Carriage Bolts →Elevator Bolts
A wide, flat, low-profile head spreads clamping force across belting to prevent cutting or tearing.
View Elevator Bolts →Hanger Bolts
Coarse wood thread one end, machine thread the other, no head — a genuine thread-transition fastener.
View Hanger Bolts →Eye Bolts
Forged, proof-tested eye replaces the head — shoulder variants rated for angular pull, plain for vertical only.
View Eye Bolts →Countersunk Bolts
Conical head seats flush with the surface, self-centering — head angle must match the mating countersink exactly.
View Countersunk Bolts →J-Bolts
A hooked embedment end cast directly into concrete, with the straight end left exposed for a fitting.
View J-Bolts →Lag Bolts
Coarse, self-tapping wood thread with a conventional wrenchable hex head — heavy timber fastening.
View Lag Bolts →Square Head Bolts
A four-flat head for period-correct or specification-mandated fastening on rail and heritage structures.
View Square Head Bolts →Shoulder Bolts
A precision-ground unthreaded diameter serves as a bearing surface for pivoting or rolling components.
View Shoulder Bolts →Machine Bolts
The general industrial workhorse form of the standard hex bolt this page describes — the default for most equipment assembly.
View Machine Bolts →Full Thread vs Partial Thread Hex Bolts
The same hex head and shank diameter, but a real, functional difference in how much of the shank is threaded.
Full Thread Hex Bolt
Threaded along the complete shank length up to the head. Ensures thread engagement regardless of the clamped material’s exact thickness, and allows the same bolt to be used across a range of joint thicknesses without risk of running out of thread.
Partial Thread Hex Bolt
A smooth, unthreaded shank section beneath the head, with threading only over a portion of the total length. The unthreaded shank diameter provides a stronger, more consistent shear-bearing surface than a threaded section would.
Hex Bolt Material & Strength Options
The standard property class ladder — always match or exceed the bolt grade to the joint’s design load requirement.
Standard Hex Bolt Configurations
Full and partial thread, metric and inch series, across the full material and grade range. M3–M64.
Full Thread Hex Bolt
Threaded the complete shank length. M3–M64. The default specification for general-purpose fastening and thin clamped joints.
Partial Thread Hex Bolt
Smooth shank beneath the head, threaded only over a portion of length. M3–M64. For shear-loaded joints requiring the unthreaded bearing diameter.
Standard Hex Bolt (Inch)
The corresponding American inch-series configuration per ASME B18.2.1, dimensionally matched to inch-thread applications across our export range.
Custom Hex Bolts
Non-standard thread pitch, custom lengths, and drawing-specific configurations in any available material. Contact sales@akbarfasteners.in with thread size and grade requirement.
Hex Bolt Size Chart — M3 to M64
Across-flats dimension and head height across the full size range.
| Thread Size | Across Flats (mm) | Head Height (mm) | Typical Wrench Size |
|---|---|---|---|
| M6 | 10.0 | 4.0 | 10 mm |
| M8 | 13.0 | 5.5 | 13 mm |
| M10 | 17.0 | 7.0 | 17 mm |
| M12 | 19.0 | 8.0 | 19 mm |
| M16 | 24.0 | 10.0 | 24 mm |
| M20 | 30.0 | 13.0 | 30 mm |
| M24 | 36.0 | 15.0 | 36 mm |
| M36 | 55.0 | 23.0 | 55 mm |
Hex Bolt Application Areas
Genuinely universal — the default fastening choice across virtually every industry we serve.
General Machinery
frame and panel fastening
Structural Steel
bolted structural joints
Automotive Assembly
chassis and body assembly
Marine & Shipbuilding
general marine hardware
Oil & Gas Equipment
general piping hardware
Rail & Heavy Transport
bogie and frame hardware
Power Generation
general plant hardware
General Industrial
across virtually every sector
Hex Bolt Standards Coverage
Same ISO 9001:2015 quality system as our complete fastener range. Across-flats dimension and thread length verified against DIN 931/933 on every production lot.
Complete Documentation Package
Grade / Standard Stated
Tensile · Proof Load
Across Flats · Head Height
Conformance
On Request
Explore Our Full Bolt & Material Range
Standard hex bolts as the baseline. Every specialty variant listed above solves one specific problem. Full material range across all product lines.
Full Bolt Range
Complete bolt manufacturing capability at Akbar Fasteners — every type covered on this page’s hub, plus wing bolts and all remaining specialty forms.
View Bolt Range →Full Nut Range
The nut side of every hex bolt joint — hex nuts, heavy hex nuts, and every specialty locking or thin-nut variant in our range.
View Nut Range →SS 316L Fasteners
For hex bolt applications in marine, coastal, or corrosive-environment duty where carbon steel’s corrosion resistance is insufficient.
View SS 316L →Hastelloy B-3 Stud Bolts
For extreme chemical-duty fastening applications where even 316L stainless is insufficient.
View Hastelloy B-3 →Need Hex
Bolts?
Thread size · grade · finish · quantity. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Export: +91 8696 32 4646 · Support: +91 800 9315 333 · export@akbarfasteners.in