Steel Sliding Gate Gear Rack, M4 and M6

Toothed steel rack for sliding gate operators, supplied in M4 and M6 module with section thicknesses from 6 to 30 mm. Standard 1 m and 2 m lengths, or cut length, hole pattern and section to your drawing.

Where a Steel Rack Is the Right Specification

Steel is the correct choice for a sliding gate when the gate is heavy, the duty cycle is commercial, or impact is a realistic possibility. It carries higher tooth load than a polymer rack, it does not creep under sustained pressure, and it does not deform if a vehicle brushes it.

The trade-off is that steel depends on lubrication and surface protection. In a dry, protected, maintained installation it will outlast a nylon rack by a wide margin. In a neglected coastal installation it may not. If you are weighing the two, our comparison of nylon and steel gate racks works through the decision on engineering grounds.

Standard Sections

These are the sections we hold as standard patterns. A is the section thickness, H the section height, and WT the weight per metre:

Section thickness is a stiffness decision rather than a strength one. A thicker section deflects less between mounting points, which keeps mesh depth consistent along the gate. If your gate frame is light or the fixing centres are wide, a thicker section is usually the better answer even when tooth load does not demand it.

Choosing Between M4 and M6

M4 covers the great majority of sliding gate installations and matches the pinion fitted to most gate operators. M6 is for heavy industrial gates where tooth load, not stiffness, is the limiting factor.

The module must match your operator pinion. It is not a preference — an M4 rack will not mesh with an M6 pinion. If you are replacing an existing rack and do not know the module, measure the distance from one tooth tip to the next along the rack and send us that figure with a photograph.

Made to Drawing

We are a transmission component manufacturer, so the standard sections above are patterns rather than limits. Produced to your drawing or sample:

• Cut length. Where a gate span does not divide neatly into 1 m or 2 m sections, end pieces can be supplied at length so the joint falls where you want it rather than where the standard length puts it.
• Hole pattern. Hole diameter, spacing and end offsets set to match an existing gate frame or a fixing line you cannot move.
• Section profile. Non-standard thickness or height where the mounting space is constrained.
• Tooth form. Module and pressure angle set to the pinion you are already using, including replacement work on installed operators.
• End preparation. Section ends prepared for butt jointing where mesh has to stay continuous across the joint.

Joints Between Sections

On a gate built from several sections, the joints are the part of the installation most likely to cause trouble. A step or gap at a joint produces a repeating knock at the same point in the travel and concentrates wear on the teeth either side of it.

Where continuity matters, tell us the total travel and how many sections you intend to use, and we will prepare the section ends so that tooth pitch carries across the joint rather than restarting at it.

Installation Notes

• Set mesh depth so the pinion engages the tooth flank without bottoming in the root. A rack pressed too deep loads the root and raises operator current.
• Keep the rack parallel to the direction of travel along the full span, not just at the ends.
• Support the rack at intervals appropriate to the section thickness. A thin section on wide centres will flex under tooth load.
• Lubricate the tooth flanks and re-lubricate on a schedule. This is the single largest factor in steel rack service life.
• Keep grit out of the mesh. Abrasive contamination in the lubricant wears both rack and pinion.

Information to Include with an Enquiry

• Module, or a tooth-pitch measurement and photograph if the module is unknown.
• Gate weight and whether use is residential, commercial or industrial.
• Total travel length and preferred section length.
• Fixing method — bolted or welded — and hole pattern if bolted.
• Site environment, particularly coastal or chemically aggressive conditions.
• Operator make and model if the rack is a replacement.

Drawings, sketches and photographs of an existing installation are all workable starting points. Send what you have and we will confirm the section, module and length before quoting.