Track Bolt

Track bolts for crawler track shoes

A track bolt holds a track shoe (the grouser plate) to the links of the track chain on a crawler machine such as an excavator, dozer or crawler loader. The nut sits in the link and the bolt goes through the shoe from the ground side. Hobson lists its track bolts and track nuts together in its earthmoving range and describes the bolts as made from high grade alloy steel for increased toughness.

These are earthmoving track bolts, not railway track bolts. The bolts that join rail at a fishplate are fishbolts, on their own page. They are also not the T-track or L-track bolts used on workbenches and cargo rails.

Dome head or hex head track bolt?

Most of our range is the dome head hex track bolt: a low, rounded head with flats, in UNF and metric fine threads. The hex head track bolt has a plain hex head and comes in 9/16 UNF x 51mm and M14 x 1.5 x 35mm. Use the head style the shoe was made for, as on the bolt you are replacing or in the machine's parts book.

Track bolt sizes, thread pitch and lengths

Every track bolt we carry, one row per bolt. Match the thread (UNF or metric fine), the diameter, the length and the head to the bolt you are replacing. Select a row to open that bolt.

UNF or metric fine thread

All our track bolts have fine threads. The imperial sizes are UNF: 20 TPI on 1/2 inch, 18 on 9/16 and 5/8, 16 on 3/4, 14 on 7/8 inch, and 12 on 1-1/8 and 1-3/8 inch. The 1 inch track bolts are 1-14 (14 TPI): Hobson lists them as UNF, but its bolt technical data chart gives standard 1 inch UNF as 12 TPI, so 14 TPI is a special (UNS) pitch. A standard 1 inch UNF nut will not fit; use the matching 1 inch track nut. The metric sizes are metric fine: 1.5mm pitch on M14 to M22 and 2.0mm on M27. An imperial track bolt will not take a metric nut, so measure the old bolt or check the parts book before you order.

Grade 9 track bolts and tightening

Every track bolt on this page is grade 9. The documents Hobson publishes for track bolts give no tensile, proof load or tightening torque figures, and Hobson's grade 9 torque table is for plow bolts only, so do not use it for track bolts. Tighten track bolts to the torque and procedure in the machine maker's service manual, and replace like with like: same grade, thread, length and head.

Track nuts to suit

Hobson's track nuts are grade 8, fine thread and supplied plain, in square, square with a round face, square stepped, square collar, hex and hex round face styles. They are made in every track bolt diameter we carry except 9/16 inch, including a 1/2 inch UNF hex track nut. The nut style has to suit the track link, so match the nut you take off.

Fitting track bolts

1. Check the old bolt for head style, thread (UNF or metric fine), diameter and length, or look it up in the machine's parts book.
2. Clean the bolt holes in the shoe and the threads and seats in the link.
3. Fit the bolt through the shoe and run on a track nut of the same thread and the style the link takes.
4. Tighten in the order and to the torque the machine maker gives.

Plain finish

Hobson supplies track bolts plain: no coating, lightly oiled to inhibit rust in the packaging and assist installation. None of our track bolts is galvanised or zinc plated.

Track bolts in Adelaide

Allmat supplies track bolts, track nuts, plow bolts and plow nuts to earthmoving contractors, plant operators and fitters across Adelaide and South Australia. Add them to a quote with the rest of your list, and we will price the lot.

Questions