FF-B-588
Hex Bolts
Mumbai · India
Finished Hex Bolts vs Heavy Hex Bolts
FF-B-588 covers two related but distinct hex bolt types, and choosing between them is mostly a question of the width across flats the joint actually needs. A finished hex bolt uses the standard head and body dimensions most general mechanical and light structural assembly is built around — it’s the bolt most people picture when they picture a hex bolt. A heavy hex bolt uses a wider head and, on larger sizes, a wider body diameter, purpose-built for heavier structural steel connections where the extra bearing surface and wrenching flats genuinely matter under higher load.
That head-size difference isn’t cosmetic — it changes what wrench or socket fits, and it changes how the bolt’s bearing area behaves under a heavily loaded structural connection compared to a general mechanical joint. Getting this choice right at the drawing stage avoids finding out on-site that the wrong hex size was ordered for the structural connection design.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our hex bolt range is manufactured in both finished hex and heavy hex types, verified by mechanical and dimensional testing under our ISO 9001:2015 quality system.
Where FF-B-588 Genuinely Applies
Unambiguous Government Specification
Removes ambiguity in federal purchase orders needing a defined general-purpose hex bolt standard.
Correctly Matched to Nut Type
Head style paired correctly to the FF-N-836 nut type and wrenching tool available on site.
Both Standard and Heavy-Duty Options
Finished hex for general assembly, heavy hex for heavier structural steel connections.
Verified Tensile & Proof Load
Batch tensile and proof load testing confirms genuine strength grade, not just correct dimensions.
FF-B-588 Type Options Explained
Standard Hex Head Bolt
Standard head and body dimensions for general-purpose mechanical and light structural assembly.
Heavy Hex Head Bolt
Wider head across flats, and on larger sizes a wider body, for heavier structural steel connections.
Full Thread / Partial (Body Bound) Thread
Full thread for general clamping applications; partial thread with a smooth shank where a precise fit in a reamed hole matters.
Bolt Type Selection Guide
The right bolt type depends on the load-bearing requirement and the wrenching tool the assembly is designed around. This table is the quick reference we use with buyers before quoting.
| Requirement | Correct Type | Key Function |
|---|---|---|
| General Mechanical Assembly | Finished Hex Bolt | Standard head/body dimensions |
| Heavy Structural Steel Connection | Heavy Hex Bolt | Wider head/body for higher bearing load |
| Precise Fit in a Reamed Hole | Partial (Body Bound) Thread | Smooth shank matches hole tolerance |
| General Clamping Application | Full Thread | Maximum thread engagement |
FF-B-588 Specification Details
Materials We Manufacture In
- Carbon Steel Grade A / Grade 5 Equivalent
- Alloy Steel Heat Treated, Higher Grade
- Stainless Steel 304 / 316
- Finish Plain / Zinc / Hot-Dip Galvanized
How Hex Bolts Are Made
- Process Hot Forged / Cold Formed
- Heat Treatment As Required per Grade
- Testing Tensile / Proof Load
- Quality Batch Sampled
Available Dimensions
- Nominal Size 1/4″ – 2″ (Inch Series)
- Metric Equivalent Available to Drawing
- Type Finished Hex / Heavy Hex
- Matching Standard ASME B18.2.1
Application Areas
Wherever a government or defense-adjacent purchase order references the specification directly.
Defense & Military Equipment
hardware requirements
Structural Steel Construction
structural steel connections
Government Infrastructure Projects
federal facility construction
Naval & Marine Equipment
procurement contracts
Machine & Equipment Assembly
general mechanical assembly
Rail & Transit Equipment
authority procurement
Bridges & Heavy Civil Works
bridge and civil connections
General Government-Contract Hardware
federally specified projects
Standard Export Documentation
Prepared as standard practice for every FF-B-588 hex bolt shipment.
Mill Test Certificate (MTC)
Heat number, chemical composition, and mechanical property verification for every lot.
Certificate of Conformance
Confirms the shipment matches the purchase order type/grade specification in full.
Tensile & Proof Load Test Records
Batch-level testing confirming genuine strength grade performance for the ordered bolt type.
Certificate of Origin (COO)
Confirms India as country of manufacture for destination customs purposes.
NABL Accredited Test Reports
Independent mechanical and dimensional testing available on request for critical applications.
Commercial Invoice & Packing List
Itemized value, Incoterm, and detailed carton/weight breakdown for customs clearance.
Internationally Recognised Standards Coverage
Related Fastener Grades & Materials
FF-N-836 Hex Nuts
The companion hex nut federal specification for the mating half of the bolted joint.
View FF-N-836 →FF-W-100 Flat Washers
Our companion federal specification flat washer range for load distribution under the bolt head or nut.
View FF-W-100 →High Tensile Bolts Specifications
Our broader metric high-tensile bolt property class reference guide.
View High Tensile Specs →Fasteners Manufacturer & Exporter to the USA
Our broader capability manufacturing to ASTM/ASME and US federal standards.
View USA Export Guide →Need Finished Hex
or Heavy Hex Bolts?
Send us your joint design, size, and grade requirement — we’ll confirm specification match, lead time, and documentation before you order. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Sales: +91 724 0000 733 · Support: +91 800 9315 333 · sales@akbarfasteners.in