Hanger Bolts
Manufacturer
India · Mumbai
Anatomy of a Hanger Bolt — A Thread Transition Fastener
A hanger bolt is a single, continuous piece of round bar with two genuinely different thread forms cut into its two ends, and no head anywhere on the part. One end carries a coarse, self-tapping wood thread — deep, widely-spaced threads similar to a lag screw’s, designed to cut its own path into wood fiber and hold firmly once driven in. The opposite end carries a standard fine machine thread, exactly like any conventional bolt, designed to accept a standard hex nut, bracket, or threaded metal fitting.
This makes a hanger bolt fundamentally a thread transition fastener — its entire purpose is to bridge two different fastening worlds, wood on one side and metal hardware on the other, in a single continuous part rather than requiring a separate wood screw plus a separate machine bolt joined by some intermediate bracket. Once the wood-thread end is driven into a pre-drilled pilot hole, the exposed machine-thread end stands proud, ready to accept whatever metal fitting, bracket, or nut the application requires.
The genuinely tricky part is installation: because there is no head anywhere on the part, there is nothing to grip directly with a wrench or driver to turn the wood-thread end into the wood. The standard solution to this is a clever reuse of the double-nutting technique — covered in full detail immediately below.
Why Hanger Bolts — One Part Instead of a Bracket Assembly
Eliminates a Separate Bracket or Adapter
Without a hanger bolt, joining a metal fitting to a wood surface at a specific point typically requires a separate mounting bracket or plate — a hanger bolt lets the metal hardware attach directly and cleanly at exactly the point the wood thread was driven.
A Genuinely Load-Bearing Wood Anchor
The coarse wood thread engages a meaningful length of wood fiber, providing real pull-out resistance for hardware that needs to bear ongoing load — furniture legs, handrail brackets, and awning mounts all rely on this wood-side holding strength.
Standard Metal Hardware on the Exposed End
Because the exposed end is an ordinary machine thread, any standard nut, washer, or threaded bracket already in a builder’s stock works directly — no special proprietary fitting is required to complete the connection.
Removable and Reattachable Metal Hardware
Once installed, the metal-side fitting can be removed and reattached repeatedly by simply working the nut — useful for furniture legs and fittings that are periodically detached for moving, storage, or maintenance.
The Double-Nut Installation Trick — Making Your Own Temporary Head
Because a hanger bolt has no head at all, there is no flat, no drive recess, and nothing a wrench can grip directly on the wood-thread end to turn it into a pilot hole. The standard solution is to thread two ordinary hex nuts onto the exposed machine-thread end and jam them tightly together — exactly the same opposed-flank double-nutting technique explained in full on our Hex Jam Nuts page, but applied here for a genuinely different purpose: not locking a joint against vibration, but creating a temporary, removable gripping point on a fastener that otherwise has nothing to hold onto.
Once the two nuts are jammed together, a wrench applied to the outer nut turns the entire assembly as a single unit — the jammed nuts, unable to slip relative to each other or to the bolt’s thread, transmit the wrench’s rotation straight down through the machine thread and drive the wood-thread end into the wood exactly as if the bolt had a proper head. After the wood-thread end is fully seated, the two nuts are simply unscrewed and removed, leaving the clean machine-thread end exposed and ready for the actual metal fitting the connection was made for.
This is a genuinely elegant piece of practical engineering: the same physical principle used elsewhere on our site purely to prevent loosening is here repurposed entirely for installation — a reminder that jammed opposed-flank nuts create a rigid, temporary mechanical assembly useful for more than just locking.
Wood Thread End vs Machine Thread End
Neither end is interchangeable with the other’s function — each is purpose-built for the material it engages.
Wood Thread End
Deep, widely-spaced threads similar to a lag screw, designed to cut and displace wood fiber as they’re driven in, gripping firmly without a pre-tapped hole — only a plain pilot hole is needed.
Machine Thread End
An ordinary standard machine thread, identical in form and function to any conventional bolt’s thread — compatible with any standard nut, washer, or tapped metal fitting already in stock.
Hanger Bolt Material & Finish Options
Grade and finish selection follows the visible/outdoor exposure of the finished assembly.
Hanger Bolt Configurations & Related Hardware
Standard dual-thread hanger bolts across the full material range, plus matched hardware. M6–M16.
Standard Hanger Bolt
Standard wood thread and machine thread combination. M6–M16, standard and custom lengths. The default configuration for furniture legs and general wood-to-metal transitions.
Matching Hex Jam Nuts
Thin hex jam nuts for the double-nut installation technique — the exact matched pair needed to drive the hanger bolt correctly. View Hex Jam Nuts →
Matching Washers & Nuts
Flat washers and standard hex nuts matched to hanger bolt thread size and finish, completing the metal-side fitting connection.
Custom Hanger Bolts
Custom overall length, wood-thread-to-machine-thread ratio, and finish. Contact sales@akbarfasteners.in with thread size, length, and application requirement.
Hanger Bolt Size Chart — M6 to M16
Machine thread size, typical wood-thread length, and matched pilot hole diameter — always confirm against actual timber species and hardware being fitted.
| Machine Thread Size | Wood Thread Length (mm) | Recommended Pilot Ø (mm) | Typical Use |
|---|---|---|---|
| M6 | 30–40 | 3.5–4.0 | Light furniture |
| M8 | 35–50 | 4.5–5.0 | Furniture legs |
| M10 | 40–60 | 5.5–6.0 | Handrail brackets |
| M12 | 50–70 | 7.0–7.5 | Heavier furniture / brackets |
| M16 | 60–90 | 9.5–10.0 | Awning / structural mounts |
Pilot hole diameter should always be confirmed against the specific timber species — denser hardwoods generally require a slightly larger pilot than softer woods at the same thread size.
Hanger Bolts Application Areas
Anywhere a metal fitting needs a direct, load-bearing connection point into wood.
Furniture Legs
removable furniture hardware
Handrail & Balustrade Brackets
staircase bracket fastening
Awning & Canopy Mounts
outdoor timber frame mounting
Playground & Outdoor Equipment
public equipment hardware
General Wood-to-Metal Fittings
a direct metal attachment point
DIY & Cabinet Hardware
general home improvement
Marine Timber Fittings
coastal timber hardware
Decorative Fixture Mounting
lighting and display fixtures
Hanger Bolt Standards & Reference
Same ISO 9001:2015 quality system as our complete fastener range. Both thread forms verified against drawing specification on every production lot.
Complete Documentation Package
Material Stated
Both Thread Lengths
Conformance
ASTM A153 (if HDG)
On Request
Related Bolt Types & Materials
Hanger bolts for wood-to-metal thread transitions. Hex jam nuts for the double-nut installation technique. Carriage bolts for wood-to-wood or wood-to-bracket clearance-hole fastening. Stud bolts for the same-thread-both-ends contrast.
Hex Jam Nuts
The exact matched pair needed to install a hanger bolt correctly — the same opposed-flank jamming principle, repurposed here for driving rather than locking.
View Hex Jam Nuts →Carriage Bolts
The through-clearance-hole alternative for wood-to-wood or wood-to-bracket joints, contrasted with the hanger bolt’s self-tapping single-thread-end embedment.
View Carriage Bolts →Stud Bolts
Another headless fastener, but with identical thread at both ends rather than a wood-to-machine transition — the flange-joint contrast case for this page’s dual-thread design.
View Stud Bolts →Lag Bolts
The single-thread, headed wood screw this page’s wood-thread end shares its coarse thread principle with — for applications needing a conventional wrenchable head instead.
View Lag Bolts →Need Hanger
Bolts?
Machine thread size · length · finish · quantity. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Export: +91 8696 32 4646 · Support: +91 800 9315 333 · export@akbarfasteners.in