Sector & Segment Gears - Gears & Drivetrain

Sector & Segment Gears

Partial gears cut as sectors where the drive only sweeps part of a circle.

Sector gears for mechanisms that swing through an arc rather than rotate - a full gear blank would be wasted material. The teeth are cut to the same class as a full gear.

AGMA 8–11 class0.5–6 module30–180 °±0.01 mm
Lead Time

4–7 weeks

Min Order

25 pieces

Certifications

ISO 9001:2015

Technical Specifications

ParameterValueUnit
Gear qualityAGMA 8–11class
Module range0.5–6module
Arc range30–180°
Pitch accuracy±0.01mm
Bore fitH7-
BlankCut from platestandard

Typical Applications

  • Steering mechanisms
  • Damper and valve actuators
  • Gate and barrier drives
  • Camera and optical drives
  • Medical bed mechanisms

Surface Finishes

  • Case hardened
  • Ground flanks
  • Passivate
  • Black oxide
  • Phosphate coated

Industries Served

  • Automotive & EV
  • Medical
  • Building Services
  • Instrumentation
  • Industrial Equipment

What drives the price of this part

Derived from the callouts on this page. Where a driver is not on the drawing, it is not on this list.

Part size
Module range at 0.5–6 module decides which machine the part lands on and how many setups it needs. Size is the driver buyers most often leave out of a first enquiry, and it is the one that changes the quote fastest.
Material
The first material listed, Carbon Steel 4140 (42CrMo4), rates 6/10 on our machinability scale at 197–235 HB annealed · 28–32 HRC quenched and tempered. On this shop's scale a harder alloy means slower passes and more tool changes, and that is cycle time the quote has to carry.
Order size
Minimum order is 25 pieces, where setup and tooling are amortised across the batch and per-part cost settles around cycle time and material. Below that quantity the same part costs more per piece, not less.

See how cycle time is calculated in the machining time calculator and what else moves a price in the cost driver reference.

How these parts are inspected

Matched to the callouts above and the instruments actually on the floor.

  • Coordinate measuring machine (Zeiss CONTURA G2, two machines, GR&R 8.4% on the critical feature)
  • Dimensional report against the drawing, with a 100% check on critical features rather than a sample
  • Certificate of conformance and the mill certificate with every shipment
  • Bore gauges and an optical comparator for hole position and edge form

The full equipment list, with counts, is on the capability page; the inspection sequence is on quality and inspection.

Questions buyers ask

Why cut a sector instead of a full gear?
Material and weight. If the mechanism only sweeps 90°, the other three quarters of the blank is dead weight on the moving part, and on a steering or medical mechanism that matters.

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