Lag Bolts

Reference illustration — produced to your drawing

Bolts

Lag Bolts

A heavy wood screw with a hex head and a coarse thread that cuts into timber. It is installed with a wrench rather than a screwdriver.

Used to join heavy timbers, ledgers, and brackets to wood. Bought by carpenters, deck builders, and structural timber contractors.

Standard

ASME B18.2.1

Size range

M6 – M20 · 1/4 – 3/4 in

MOQ

From 50 pcs

Lead time

Samples 5–10 days

What we produce

  • Carbon steel or stainless steel 304
  • Hex head with coarse wood screw thread
  • Metric or inch lag thread forms
  • Hot-dip galvanized or zinc finish

Specification notes

  • Common lengths from 25 mm to 300 mm
  • Often paired with a flat washer
  • Galvanized option for outdoor and treated timber

Specifications

Every line below is a starting point, not a limit. Non-standard sizes, special threads and unusual materials are what we do — send the drawing and we confirm what fits.

StandardASME B18.2.1
Size rangeM6 – M20 · 1/4 – 3/4 in
ThreadsWood screw thread (lag thread) · Metric · UNC
Head / geometryHex head; driven by a hex wrench or socket
MaterialsStainless steel 301 / 303 / 304 / 304L / 316 / 316L / 410 / 416 / 17-4PH · carbon steel 1045 / 1215 / 12L14 · alloy steel 4130 / 4140 · aluminium 2024 / 5052 / 6061 / 7075 · brass · bronze · copper · titanium
FinishesAs machined · black oxide · zinc plating · nickel plating · chrome plating · anodizing · passivation (through our vetted partner network)
Precision±0.01 mm on features that locate, seal or fit; ISO 2768-m for general dimensions
MarkingHead marking, grade marking or your own identification mark per drawing
DocumentsMaterial certificate (MTR) with every batch, plus pre-shipment photos before dispatch
MOQFrom 50 pieces per type and material · samples from 1 piece
Sample lead time5–10 days
Production lead time25–35 days after sample approval
QuoteWithin 24 hours, with DFM feedback

Standard dimensions

Metric hex head bolts and screws — nominal dimensions (ISO 4014 / ISO 4017)

dPitch (mm)s (mm)k (mm)e (mm)
M50.883.58.79
M61.010411.05
M81.25135.314.38
M101.5166.417.77
M121.75187.520.03
M162.0241026.75
M202.53012.533.53
M243.0361539.98
M303.54618.750.85
M364.05522.560.79

d = nominal thread diameter · s = width across flats · k = head height · e = width across corners. Nominal values; your drawing always takes precedence.

Other bolts we manufacture

See all 179 part types →

Send us the drawing

We reply within 24 hours with DFM feedback, a process route and a price. Samples from 1 piece, production from 50 pieces, shipped from Qidong City, Jiangsu Province, China.

Request a quote