We are a China-based precision machining workshop focused on copper-alloy components,
supplying CNC machined bronze in China and worldwide to OEM builders, gearbox manufacturers,
valve works, pump producers and maintenance teams. Send a drawing, a physical sample or a 3D
model, and we machine the bronze part to specification — from a single prototype to
long-running, high-volume series production.
A Bronze Machining Partner Built Around OEM Requirements
Bronze is not a side material for us — it is one of the material groups we machine every
day. Tin bronzes, phosphor bronzes, leaded bearing bronzes, aluminum bronzes and
high-strength manganese bronzes each behave differently under the cutting tool: they pull
heat away differently, form chips differently and call for dedicated tool geometry,
coolant strategy and work-holding. Our process planning starts from those differences so
that bores stay round, threads stay clean and mating surfaces hold their tolerance across
an entire production batch.
Every order is built to the customer's own drawing. We select the matching grade under a
GB/T, ASTM/SAE, EN/DIN or JIS designation, machine from centrifugally cast tubes,
continuously cast hollow bars, extruded rods or customer-supplied castings, and finish the
part ready for assembly. For buyers sourcing CNC machined bronze in China, this means one
accountable workshop for material selection, machining, inspection and surface preparation.
Parts leave the workshop clean, deburred and dimensionally checked against the drawing,
with thread systems, fit tolerances and cosmetic requirements agreed before the first cut.
In-house processes
Complete CNC Machining Capabilities for Bronze Parts
A single bronze component often combines turned diameters, milled flats, cross-holes and
internal threads. Keeping these processes in one controlled workflow reduces repeated
set-up error and protects the relationship between features.
CNC Turning
OD and ID turning, facing, grooving, boring, parting-off and single-point threading on bar
stock, cast tubes and billets. This is our main process for bearing bushes, sleeves,
flanged bushes, spacer rings, valve seats, threaded nuts and every circular component where
concentricity, cylindricity and a fine surface finish matter.
CNC Milling — 3-Axis, 4-Axis & 5-Axis
Three-axis milling handles planes, pockets and prismatic features; four-axis indexed
machining completes features around a part in a single set-up; five-axis machining reaches
compound angles and continuous contours such as worm-wheel tooth geometry, helical pockets
and complex valve bodies. Fewer set-ups mean tighter feature-to-feature accuracy on every
CNC machined bronze part.
Drilling & Reaming
Straight holes, cross-holes, angled holes and deep holes are produced by spot drilling,
drilling, boring and reaming, with counterboring and countersinking where fasteners seat.
Hole position, diameter consistency and internal surface quality are controlled to drawing,
including intersecting oil galleries and lubrication channels typical of bronze bearings.
Tapping & Threading
Internal threads are produced by tapping, thread milling or single-point threading,
depending on size, pitch and alloy. We work to metric M threads, unified UNC/UNF/UNEF,
British BSP/G parallel and NPT tapered threads, and threads are checked against the
corresponding limit gauges before parts leave the workshop.
Materials
Six Bronze Families Machined Every Day
“Bronze” covers a broad family of copper alloys. The cross-reference table in the
next section maps common commercial grades across national standards, while these cards
summarize how each family typically behaves and where it is used.
Tin Bronze (Cu–Sn)
The classic bearing and gear material, combining good strength with wear resistance and
corrosion resistance in water, steam and mineral oils. Typical parts include gear blanks,
worm wheels, bushes, sealing rings and valve trim.
Phosphor Bronze (Cu–Sn–P)
Phosphorus raises stiffness, fatigue resistance and spring-like behavior, while tin
provides low-friction wear performance. It suits fine-pitch gears, lead-screw nuts, spring
seats, contact components and parts with thin walls or precise internal threads.
Leaded Bronze (Cu–Sn–Pb)
Finely dispersed lead gives excellent anti-seizure, conformability and embeddability,
making leaded bronzes the default choice for boundary-lubricated bearings and bushes under
mixed load and speed conditions, including crankshaft and pump bearings.
Aluminum Bronze (Cu–Al–Fe)
Among the strongest copper alloys, with high hardness, outstanding corrosion and erosion
resistance and reliable behavior in seawater and aggressive fluids. Used for impellers,
spindles, flanges, heavy gears, valve bodies and high-duty couplings.
Nickel-Aluminum Bronze (Cu–Al–Fe–Ni)
Nickel additions raise strength, toughness and seawater corrosion resistance further. This
family handles the most demanding marine, offshore and heavy-engineering duties: propeller
hardware, winch components, large valve bodies and high-torque gears.
Manganese Bronze (Cu–Zn–Mn–Al)
A high-tensile, high-toughness alloy family used where loads are heavy and shock is
present. Typical machined parts include brackets, levers, coupling halves, lifting
hardware, gear racks and slow-speed, heavy-load gears.
Grade cross-reference
Commercial Bronze Grades Across National Standards
Customers order CNC machined bronze in China under different designation systems. The table
below maps the commercial grades we machine most often; the named standard printed on the
drawing always governs chemistry, temper and acceptance values.
Alloy family
China GB/T 1176 / QB
USA ASTM B505 · SAE · CDA
Europe EN 1982 / DIN 1705
Japan JIS H5120 / H5121
Typical application
Tin gunmetal
ZCuSn10Zn2
C90500 · SAE 62
CuSn10Zn2-C / G-CuSn10Zn (RG10)
BC3 · CAC403
Gears, valves, pump bodies and sealing rings
Leaded bearing bronze
ZCuSn5Pb5Zn5
C93200 · SAE 660
CuSn7Zn4Pb7-C · CC493K (RG7)
BC6 · CAC406
General bushes, plain bearings and thrust washers
High-lead bronze
ZCuPb15Sn8 / ZCuPb10Sn10
C93700 · SAE 64
CuPb15Sn8-C · CC496K / G-CuPb15Sn
LBC series (LBC2–LBC5)
High-speed bearings and thin-wall bushes
Cast phosphor bronze
ZCuSn10P1; QSn6.5-0.1 (wrought)
C90700 · SAE 65; C54400 (wrought)
CuSn11P-C / G-CuSn12 (2.1052)
PBC2 · CAC602
Worm wheels, gears and lead-screw nuts
Aluminum bronze
ZCuAl10Fe3; QAl9-4 (wrought)
C95400
CuAl10Fe2-C · CC331G / G-CuAl10Fe
ALBC2 · CAC702
Impellers, spindles, flanges and valve bodies
Nickel-aluminum bronze
ZCuAl9Fe4Ni4Mn2
C95800 / C95500
CuAl10Fe5Ni5-C · CC333G / G-CuAl10Ni
ALBC3 · CAC703
Marine hardware, heavy gears and seawater valves
Equivalences are indicative rather than identical — neighboring standards differ slightly in
chemistry and mechanical values. The exact grade, temper and chemistry are confirmed on the
order documentation before production starts.
Batch flexibility
From a Single Spare Part to High-Volume Series
The same CNC equipment and inspection discipline apply whether the order is one replacement
bush or a standing monthly production release.
1
One-Off Parts & Prototypes
Single replacement parts, first articles and engineering prototypes are machined from a
drawing or a reverse-engineered sample, including obsolete bushes and worm wheels with no
spare available on the market.
2
Small Batches
Runs from a few pieces to several hundred suit machine builders, maintenance stocks and
product development. Simple jigs and soft jaws keep set-up time and unit cost under
control.
3
Recurring Serial Production
Repeat batches run from fixed set-up sheets and proven tooling lists, so parts from the
sixth release match parts from the first in size, finish and appearance.
4
High-Volume Production
For ongoing demand we optimize fixturing, use bar-fed turning and multi-part milling
cycles, and plan production in stable lots to support releases of thousands or tens of
thousands of pieces.
Secondary operations
Finishing Operations That Make a Part Assembly-Ready
Machining is followed by the smaller operations that decide whether a bronze part is truly
ready to fit on the customer's line.
Boring & Reaming
Precision bore sizing and fine internal surfaces for press-fit and running clearances.
Keyway Broaching
Internal keyways, slots and spline preparations on bushes, hubs and gear blanks.
OD, ID & Surface Grinding
Size correction and fine finishes after heat treatment or for tight-fit mating parts.
Honing & Lapping
Controlled bore geometry and low-roughness running surfaces for bearing applications.
Thread Milling
Accurate internal and external threads, including large diameters and coarse pitches.
Deburring & Edge Breaking
Burr removal at cross-holes and controlled edge breaks on every exposed edge.
Polishing & Satin Finishing
Uniform cosmetic surfaces, from brushed satin finishes to mirror polishing.
Part Marking & Packaging
Grade or lot marks, moisture-protective treatment and separated export packaging.
How an order flows
A Six-Step Path From Drawing to Delivery
1
Drawing Review & Grade Selection
Geometry, tolerances and service conditions are reviewed, then the bronze grade and stock
form — cast tube, continuous-cast bar or wrought rod — are confirmed.
2
Quotation & Machinability Feedback
The quote lists process route, stock allowance and lead time. Where a feature is expensive
or risky to machine, it is flagged with alternatives before production begins.
3
First-Article Machining
A first article is machined and fully inspected; critical dimensions are recorded and
confirmed with the customer before the batch is released.
4
Batch Production
Approved processes, tooling and offsets are repeated across the batch, with in-process
checks at set intervals on diameters, hole positions and threads.
5
Finishing & Final Inspection
Deburring, finishing and cleaning are completed, followed by final dimensional inspection,
thread gauging and a visual check against the drawing.
6
Packaging & Dispatch
Parts are dried and protected against moisture, packed to avoid contact damage and
prepared for domestic or international freight.
Industries served
Where Our Bronze Components Work
Gearboxes & Power Transmission
Worm wheels, worm-gear rims, gear blanks, bearing housings and shaft sleeves for
reducers, conveyors and transmission equipment.
Hydraulics, Valves & Fluid Power
Valve seats, sleeves, gland bushes, distributor bodies and threaded inserts for hydraulic
and pneumatic systems.
Pumps & Compressors
Impeller wear rings, shaft sleeves, throat bushes, sealing seats and wearing rings for
water, oil and chemical media.
Marine & Offshore Engineering
Seawater valve parts, propeller-shaft bushes, winch and crane components in aluminum and
nickel-aluminum bronze.
Agricultural & Construction Machinery
Pivot bushes, linkage sleeves, hinge bearings and wear plates for dusty, shock-loaded
working conditions.
Material Handling & Lifting Equipment
Sheaves, pulley bushes, hoist gears, elevator components and crane slewing bearings under
continuous cyclic load.
Why customers choose us
Why Buyers Source CNC Machined Bronze in China From Our Workshop
Copper-Alloy Machining Focus
Dedicated tool geometry, sharp cutting edges and a coolant practice tuned to soft,
heat-pulling bronze alloys — for clean chips, unmarred surfaces and stable bore sizes.
Full Grade Range in One Place
Cast and wrought bronzes across GB/T, ASTM/SAE, EN/DIN and JIS designations, sourced as
centrifugal tube, continuous-cast bar, plate or customer-provided casting.
Turning & Multi-Axis Milling Together
Turned, milled, drilled and threaded features are finished in one routing, removing the
tolerance stack-up that comes from splitting work between several shops.
Tolerance & Finish Discipline
Features are held to drawing, commonly in the IT6–IT8 range with turned surfaces
around Ra 1.6–3.2 µm; critical dimensions are recorded for first articles.
Any Quantity, Same Standard
One-off reverse-engineered spares and long-term volume programs run on the same machines,
with the same inspection mindset from first cut to final piece.
Export-Ready Working Habits
English drawing communication, metric and inch threads, neutral or customer-branded
packaging and production planning aligned to sea-freight schedules.
Machined products
Examples of CNC Machined Bronze Parts
A small selection of bronze components produced on our workshop floor.
Worm Wheel
Bearing Bush
Rob Bushing
Questions buyers ask
Frequently Asked Questions
Which bronze grade is right for my bearing?
It depends on load, sliding speed, shaft hardness and lubrication. Leaded tin bronzes such
as C93200 / SAE 660 suit general boundary-lubricated bushes; high-lead grades suit high
speed with limited lubrication; phosphor bronzes suit gear and wear duty; aluminum bronzes
are chosen for strength and corrosion resistance. A grade can be suggested once the
application conditions are known, while the final designation follows your drawing or
engineering standard.
Can you machine castings we supply ourselves?
Yes. We machine customer-supplied sand castings, centrifugal castings, forgings and
extruded stock, and we can also source matching stock ourselves. For bushes and rings,
centrifugally or continuously cast hollow bar removes far less material than a solid
billet and shortens cycle time.
What tolerances and surface finishes are realistic?
General machined features are commonly held in the IT6–IT8 range; turned bearing
bores can be controlled more tightly where fit and roundness require it, and turned
surfaces routinely reach Ra 1.6–3.2 µm. The binding values are always the
tolerances marked on your drawing.
Can bronze be combined with steel in one assembly?
Yes. Common examples include bronze worm-wheel rims mounted on cast-iron or steel hubs,
bronze bushes pressed into steel housings, and steel shafts running against machined bronze
sleeves. We machine the bronze component to the interference or clearance fit your assembly
requires.
Machining Bronze the Way OEM Applications Demand
Whether the requirement is a single obsolete worm wheel or a standing monthly release of
bearing bushes, every CNC machined bronze part from our China workshop follows the same route:
the correct grade, the right combination of processes, disciplined inspection and
assembly-ready finishing. Buyers looking for CNC machined bronze in China can build a complete
bronze-component program with us — prototype, batch and high-volume production alike.