Q&T Helical Rack

Smoother Engagement

The 19°31’42” helix angle ensures gradual tooth-to-tooth contact. This eliminates the harsh impact loading that plagues straight racks at higher traverse speeds, reducing vibration levels that would otherwise shorten bearing and servo motor life.

DIN 8 Grade 7 Precision

Pitch deviation is held within DIN 8 Grade 7 tolerances across the full rack length. For gantry routers and laser cutting tables operating across travel distances of 500 mm to 1,000 mm per section, this directly translates into tighter positional accuracy and consistent surface finish on workpieces.

Q&T Heat Treatment HB 20–25

Quench and temper treatment converts the S45C billet to a core hardness of HB 20–25. This balanced hardness profile provides excellent wear resistance at the tooth surface while retaining sufficient toughness in the body to withstand shock loads without fracture — critical in press automation and transfer line applications.

Four-Side Flat Ground Body

All four longitudinal faces of the rack body are flat-ground after heat treatment, not just the tooth face. This means the rack mounts flush against its carriage or bed without shimming, and multiple rack sections butt together accurately — a practical benefit when building long travel axes from standard 500 mm or 1,000 mm sections.

Wide Module Range (1.5 to 12)

With modules from 1.5 up to 12, this helical rack series covers everything from a compact 100 mm wide gantry on a PCB router through to a 120 mm body rack driving a 10-tonne press feed axis. Tooth counts per section and hole patterns are proportioned to maintain structural integrity across the full module range.

No-Hole Option Available

For applications where through-hole positions conflict with structural members or seal arrangements, a no-hole variant is available by adding “N” as a suffix to the standard model code (e.g. 662 010 050N). This preserves full cross-sectional area along the rack body for maximum rigidity in mounting zones where hole positions cannot be tolerated.

● Material: S45C Medium-Carbon Steel

S45C is a JIS-grade medium-carbon steel equivalent to C45E under EN 10083. Its carbon content of approximately 0.42–0.48% gives it an excellent balance of machinability and hardened strength. After Q&T treatment the rack body reaches HB 20–25, and the structured grain boundary of the quenched steel resists fatigue crack propagation even under cyclic loading in high-cycle automation equipment. Its modest alloy composition also keeps costs predictable for volume purchases.

● Operating Principle: Helical Engagement

When a helical pinion meshes with this helical rack, contact begins at one end of the tooth and progresses diagonally across the face width as the pinion rotates. Because the contact line is inclined at the helix angle, load is shared simultaneously across multiple teeth at any given moment. This overlap ratio means that as one tooth pair exits engagement, the next is already sharing the load — removing the abrupt torque spikes that characterise straight-tooth mesh. The result is a noticeably quieter, lower-vibration drive train suitable for noise-sensitive environments such as medical device assembly and food processing machinery.

● Application Scenarios Across UK Industry

This helical rack finds its home in CNC gantry routers, plasma and laser cutting tables, pick-and-place robotic cells, automated pallet transfer systems, heavy-duty stage-lift machinery (theatres and event venues across London and the Midlands frequently specify DIN 8 Grade 7 for their lifting drives), and in agricultural machinery adjustment systems where smooth motion without operator-felt vibration is a key comfort requirement. Module 8 and 10 variants are particularly popular in UK steel fabrication and shipbuilding tool-slide applications where rack travel can exceed 5 metres.

Custom Module
Non-standard modules on request

Custom Length
Cut-to-length & spliced sets

Surface Coatings
Black oxide, zinc phosphate

Material Certs
Full inspection report supplied

“

We had been through two suppliers trying to solve the noise issue on our transfer press. Switching to the helical rack made an immediate and audible difference. The pitch accuracy across 6 metres of joined sections is genuinely impressive — we haven’t had to shim a joint yet.

— James H., Maintenance Engineer
Automotive Stamping, Birmingham, UK

“

We specified the Module 4 helical rack for a new gantry router build — the DIN 8 Grade 7 tolerance held across three rack sections butted together perfectly. Positioning repeatability at 0.05 mm over a 3-metre travel was what our customer demanded, and we hit it first time. Lead time from order to delivery was eight working days, which kept our build schedule on track.

— David M., Design Engineer
CNC Machine Builder, Sheffield, UK

“

Our stage lift system in Manchester needed a helical rack that could handle 8-tonne loads with minimal backlash growth over thousands of cycles. The Q&T treatment on Module 10 was the deciding factor. Two years into operation and we have seen no measurable wear on either the rack or the pinion. We’ll be specifying this product on all future builds.

— Rachel T., Project Manager
Stage Machinery & Lifting, Manchester, UK

A straight-cut rack engages one tooth pair at a time, creating a brief impact at each tooth entry that generates vibration and noise. A Q&T helical rack, by contrast, uses a 19°31’42” helix angle so the contact line sweeps gradually across the tooth face, meaning two or more tooth pairs always share the load. For a CNC router operating at rapid traverse speeds, this translates into smoother servo current curves, less mechanical noise on the factory floor, and — critically for UK machine builders — better surface finish on the workpiece because the drive axis is not exciting resonances in the machine structure.

Pricing depends on module size, rack length, and order quantity. Module 1.5 sections in 500 mm lengths will cost considerably less per metre than Module 10 in 1,000 mm lengths due to material volume and machining time. For an accurate price and to confirm stock availability for UK delivery, the most reliable route is to email sales@farm-equipment-parts.com with your module, length requirements, and approximate quantity. Quotes typically come back within 24 hours.

For a plasma cutting gantry at 20 m/min traverse, Module 3 or Module 4 helical rack is the most common choice in UK machine builder practice. Module 3 gives a compact cross-section suitable for lighter gantry structures, while Module 4 provides more tooth depth and higher load capacity if the gantry carries a heavy plasma torch carriage or dual-sided drive. The DIN 8 Grade 7 pitch accuracy in both modules is more than sufficient for the positioning demand of plasma cutting. Match the pinion tooth count to your servo motor reducer ratio to keep pitch-line velocity comfortably within the manufacturer’s recommended surface speed range.

Farm Equipment Parts supplies Q&T helical racks to UK engineering businesses across Birmingham, Sheffield, Manchester, and London, with standard sections typically dispatched within 5–10 working days. For custom modules, lengths outside the catalogue, or no-hole variants, lead times of 15–20 working days apply. Contact the sales team at sales@farm-equipment-parts.com with your drawing or specification sheet, and the team will confirm feasibility, price, and delivery schedule directly.

Ball screws become impractical beyond approximately 4–5 metres of travel because the screw shaft begins to resonate (whip) at higher rotational speeds, limiting traverse velocity. A helical rack and pinion drive has no such length limitation — crane traversing systems and gantry systems across the UK routinely run rack axes of 10–20 metres or more. The helical rack also transmits higher force per unit weight of drive hardware, making it the standard choice for heavy structural steel fabrication positioners, automotive body-in-white transfer lines, and port handling equipment where long travel, high load, and moderate to high speed must co-exist.

S45C is a JIS medium-carbon steel (roughly equivalent to C45 in the EN system) with approximately 0.45% carbon. Q&T — Quench and Temper — is a two-stage heat treatment: the steel is heated above its transformation temperature, quenched rapidly in oil or water to create a martensite structure, then re-tempered at a lower temperature to relieve internal stresses and achieve a controlled hardness in the HB 20–25 range. In food processing equipment installed in UK factories (subject to BRC Global Standard audits), S45C Q&T racks are used in non-contact zones such as overhead gantry drives and pallet conveyors. The balanced hardness means the rack resists the grit and abrasive cleaning compounds used in washdown regimes while remaining tough enough to tolerate the occasional shock loading from product jams.