T-Slot Bolts M22 - M42 T Track Bolts 70mm to 500mm Long GRADE 8.8 HIGH TENSILE

Measure the total stack height of all components the bolt must pass through — workpiece, clamp body, T-nut, and any spacers — then add 1–1.5× the thread diameter for adequate nut engagement. For example, a 30 mm stack with an M24 bolt would call for roughly 54–66 mm of thread engagement, so a 100 mm bolt gives comfortable clearance. When in doubt, size up one increment; excess thread can be managed with a standard hex nut, but a bolt that's too short cannot clamp safely.

Grade 8.8 is an ISO strength classification indicating a minimum tensile strength of 800 MPa and a yield strength of 640 MPa. In practical terms, an M24 Grade 8.8 bolt can sustain a proof load exceeding 100 kN before permanent deformation. For woodworking jigs, router tables, and light-to-medium CNC fixtures, Grade 8.8 is more than adequate. For heavy press or structural applications with dynamic shock loads, consult an engineer about Grade 10.9 or 12.9 alternatives.

T-slot bolt head dimensions are matched to specific channel widths. Common T-slot profiles use 6 mm, 8 mm, 10 mm, and 12 mm slot widths. Before ordering, measure the opening width of your T-track channel and confirm the head width of the bolt you're selecting. If you're unsure, contact us with your extrusion profile specification and we can advise on compatibility.

Yes — that's the core advantage of a T-slot bolt. Loosen the nut slightly, slide the bolt along the channel to the new position, then re-torque. The head remains captured in the slot throughout, so you don't need to disassemble the fixture. This makes T-slot bolts ideal for adjustable jigs and workholding setups that change between jobs.

The surface finish provides basic protection against workshop humidity and incidental moisture, but these bolts are not rated for continuous outdoor exposure, salt spray, or immersion. For outdoor or marine environments, consider stainless steel alternatives. For indoor fabrication shops with coolant mist, wiping the bolts dry after use and applying a light oil film will extend service life significantly.

Recommended torque depends on thread diameter and lubrication condition. As a general reference for Grade 8.8 bolts with a dry, clean thread: M22 ≈ 430 N·m, M24 ≈ 580 N·m, M27 ≈ 840 N·m, M30 ≈ 1,150 N·m. For T-slot workholding applications where the goal is clamping force rather than structural joint integrity, many users apply 30–50% of the full proof torque to avoid distorting aluminum extrusion channels. Always use a calibrated torque wrench for repeatable results.

A standard metric hex nut of the matching thread size will thread onto these bolts correctly. However, for T-slot applications, a T-nut or flange nut is typically used on the opposite side of the channel to distribute clamping load across the extrusion wall. Using a standard hex nut alone may concentrate stress on a small contact area. We recommend pairing these bolts with the appropriate T-nut for your profile to get the best clamping performance.