T-Slot Bolts T-Slot Screws Black 8.8-12.9 Steel M12 M14 M16 M18 M20 M24 M30

Match the thread diameter to the nut or threaded insert you're using in your extrusion assembly. For lighter structural frames (workbenches, enclosures), M12–M16 is typically sufficient. For heavy-duty gantries, fixture tables, or load-bearing joints, M20–M30 provides greater clamping force and shear resistance. Always cross-reference with your extrusion manufacturer's recommended fastener spec for the profile series you're using.

Grade 8.8 bolts are made from medium-carbon steel and have a minimum tensile strength of 800 MPa — suitable for most general structural and mechanical assemblies. Grade 12.9 bolts are made from alloy steel and heat-treated to a minimum tensile strength of 1220 MPa, making them the right choice for high-load joints, vibration-prone environments, or applications where a smaller bolt diameter must carry a larger load. If in doubt, Grade 12.9 gives you more margin.

These bolts are designed for standard metric T-slot aluminum extrusion profiles. The hammer-head width must match your profile's slot opening. Common slot widths are 6 mm (2020 series), 8 mm (3030/4040 series), and 10 mm (larger industrial profiles). Measure your slot opening before ordering, or contact us to confirm compatibility with your specific extrusion series.

Black oxide provides mild corrosion resistance by converting the surface iron to magnetite, which slows oxidation in dry or low-humidity indoor environments. It is not equivalent to zinc plating or stainless steel for outdoor or high-moisture applications. For outdoor or washdown environments, consider applying a light oil or using stainless hardware instead.

Yes — that's one of the core advantages of T-slot hardware. As long as the bolt has not been fully torqued to its final clamping load, you can loosen it and slide it along the channel to a new position. This makes T-slot bolts ideal for iterative builds, adjustable fixtures, and modular frames where component positions change over time.

Recommended torque depends on the thread diameter and grade. As a general reference: M12 Grade 8.8 ≈ 80–90 Nm; M16 Grade 8.8 ≈ 190–210 Nm; M20 Grade 8.8 ≈ 370–400 Nm. Grade 12.9 bolts can accept approximately 40–50% higher torque values than Grade 8.8 of the same diameter. Always consult a torque specification table for your exact diameter/grade combination and apply torque gradually with a calibrated torque wrench.

These T-slot bolts are designed to be used with a T-nut or roll-in nut that sits inside the extrusion channel, or with a threaded insert pressed into the profile. The bolt itself does not thread directly into the aluminum — the T-nut provides the threaded engagement. T-nuts are sold separately; contact us if you need help selecting the correct T-nut for your profile series.