Gear Reducer Manufacturer in Zhejiang: How to Check a Supplier

A gear reducer manufacturer is not hard to verify, but almost nobody asks the right questions. Four of them settle it: where the factory is, which machining operations happen inside it, how wide the catalogue actually is, and whether the supplier will put a type designation and a torque calculation in writing before taking the order. This page sets out seven checks you can apply to any supplier, and answers each one with our own figures. Yanfeng Group Co., Ltd. has built gear reducers and plastic weaving machinery in Pingyang, Wenzhou, Zhejiang since 1987; every number below comes from our company data and our series catalogues, which are downloadable from each series page.

Key definitions

• Manufacturer: the company that cuts, heat-treats, grinds and assembles the gears, and whose name is on the nameplate. Not the same as the exporter or the agent who quotes you.
• Gear reducer (gear unit): a gearbox that lowers the motor's speed and multiplies its torque by the ratio i.
• Permissible output torque T2: the torque a frame size is rated for continuously at a given ratio — the figure in the selection table, not a peak.
• Type designation: the coded model string (series, mounting, frame size, motor, ratio, mounting position, shaft side) that defines exactly what will be shipped.
• Hardened tooth flank: gearing that is carburised, quenched and then precision-ground, which requires gear grinding machines on site.
• Frame size: the standard size number (37, 47, 57 …) shared across the industry, which is what makes cross-brand replacement possible.

Seven checks, and our answers

#	What to check	Why it matters	Yanfeng Group
1	Factory address, not an office address	An agent can quote any catalogue; only a maker can be visited and audited	Wuyang Industrial Zone, Pingyang, Wenzhou, Zhejiang, 325401 — 60,000 m² of construction area
2	Which operations are in-house	Gear grinding and hobbing done outside the factory means tolerances the supplier does not control	200+ machine tools, 60+ of them high-precision CNC machines and test machines; gear hobbing, gear grinding, CNC machining centres and dedicated assembly workshops on site
3	Catalogue breadth against your torque	A supplier with one family will push you onto the wrong shaft arrangement	Nine series, 87 N·m to 2,600,000 N·m (table below)
4	Will they write a selection calculation	Sizing by ratio alone, without service factors, is how a reducer ends up undersized in service	Selection to T2 ≥ T1 × f1 × f2 × f3, the method in every series catalogue and in our gear reducer selection guide
5	Quality and environmental certification	ISO 9001 is the minimum; ISO 14001 and CE tell you the plant is audited more than once	ISO 9001:2015, ISO 14001, CE certification for machinery, National Intellectual Property Management System certification
6	Own designs, or copies	Patents and an R&D centre mean the supplier can change a design for you	109 national invention and utility-model patents; provincial high-tech enterprise R&D centre; National Intellectual Property Advantage Enterprise (State Intellectual Property Office)
7	Export record and spare-parts channel	A reducer outlives the order; you need parts in five years	80+ countries and regions served, including Nigeria, Egypt, Algeria, Kenya, Uzbekistan, India and Brazil; a standing After-sales & Spare Parts division

The nine series we build in Pingyang

Series	Construction	Sizes	Power / speed	Output torque
R series	Coaxial (in-line) helical	R17–R167 (13)	0.12–160 kW	87–17,700 N·m
F series	Parallel-shaft helical	37–157 (10)	0.12–200 kW	196–16,800 N·m
K series	Right-angle helical-bevel	K37–K187 (12)	0.18–200 kW	156–49,400 N·m
S series	Right-angle helical-worm	S37–S97 (7)	0.12–22 kW	93–3,990 N·m
P series	2- or 3-stage planetary, power splitting	9–36	0.4–1,293 kW; 0.19–60 r/min out	up to 2,600,000 N·m
H/B series	Modular 1–4 stage helical (H) or bevel-helical (B)	1–22	2.52–5,366 kW; 1.7–1,200 r/min out	up to 470,000 N·m
ZDY / DBY series	Hardened-tooth cylindrical and bevel-cylindrical, to national standards	ZDY 80–560, ZLY 112–710	ratios 1.25–100 (cylindrical), 8–50 (bevel)	per centre distance and stage count
T series	Spiral bevel 90° steering box	T2–T25 (10)	ratios 1:1 to 5:1; 2–488 kg	≈11.6–3,499 N·m rated
SWL series	Self-locking worm-bolt lifter	YFSWL1–YFSWL100 (11)	travel 300–2,000 mm	lifting force 10–1,000 kN

Four construction points are shared across the whole range: precision-ground gears in high-quality alloy steel, high-grade ball bearings, a three-layer high-density polymer paint finish that seals out dust and tolerates high temperature, and the standard frame-size and ratio designations that make a unit interchangeable. Full power, ratio and torque tables, the type-designation key and the M1–M6 mounting drawings are in the catalogue PDF on each series page.

What "in-house" means on our site

Check 2 is the one that separates manufacturers from assemblers, so it is worth being specific. Our machining list includes a CNC gantry machining centre for large tape-drawing die heads, a CNC horizontal machining centre for critical parts, five five-axis milling machines and seven four-axis CNC centres for circular-loom components, a computerised balancer for roller balance testing, gear hobbing machines, gear grinding machines and a separate detection device for inspection. Assembly runs in dedicated workshops rather than a shared floor. You can see the shop photographs and the equipment list on our production capacity page, and the company history on the about page.

The practical consequence for a reducer order is that hardened tooth flanks, which have to be carburised, quenched and then ground, are produced and measured on equipment we own, so the tolerance you are quoted is the tolerance we control.

Our recommendation for sourcing a reducer

Do not start from a brand or a country. Start from five numbers — required output speed, required output torque, duty hours per day, starts per hour, and the mounting orientation the machine frame allows — then ask two or three suppliers to return a type designation and the permissible torque for that designation. A supplier who answers with a model number but no torque figure has not done the calculation, and a supplier who cannot name their own gear-grinding equipment is reselling someone else's gears. Both are knowable before you place the order, and both are cheaper to find out now.

Send those five numbers, or simply describe the machine and its duty, through the enquiry form. Our Reducer Sales department and engineers return a selection, a permissible-torque figure and a dimension drawing. The full range is listed under gear reducers; office hours are Monday to Saturday 08:00–17:30 and Sunday 09:00–17:30, China Standard Time (UTC+8).