Terminal studs and pins
Turned studs, pins and stems that carry current through a housing or bushing.
For breakers, transformers and bushings
Turned and machined copper parts, made to your drawing.
CNC turned and milled parts in pure copper and copper alloys, from terminal pins to machined contact arms. Manufactured in India, plated and inspected against your drawing, and delivered to your Incoterm.
- Pure copper or copper alloys
- Threads gauged
- Measured records
Terminal pin, M8, silver platedDWG REV. B
- Material
- ETP copper C11000, half-hard
- Plating
- Silver, 5 µm minimum
- Critical dimension
- Ø12.00 h9, thread M8 6g
- Inspection
- Thread gauged, go and no-go
What we make
Connector bodies and sockets
Machined sockets, plug pins and connector bodies, plated for a low contact resistance.
For power connectors and plug-in switchgear
Machined terminals and blocks
Milled, drilled and tapped terminals cut from solid copper bar.
For high-current joints and transitions
Contact arms and fingers
Machined contact arms and fingers in copper and copper chromium.
For ACB and isolator contact systems
Welding electrodes and caps
Resistance welding electrodes, caps and holders in copper chromium zirconium.
For spot and projection welding lines
Cold plates and heat spreaders
Machined copper blocks and plates that take heat away from power devices.
For inverters, chargers and data-centre power
Choosing a copper
Pure copper carries the most current. Alloys machine faster or keep their strength when hot.
Material for the job
- ETP copper C11000
- The standard conductor, at 100% IACS.Watch for: Soft and gummy to machine; burrs and finish need care.
- Oxygen-free copper C10200, C10100
- For parts that are brazed, welded or used in hydrogen or vacuum.Watch for: Costs more; use it only where the joint needs it.
- Tellurium copper C14500
- Free-machining copper at about 93% IACS, for fine threads and many features.Watch for: Not for parts that are welded.
- Copper chromium zirconium C18150
- Keeps its strength and hardness when hot, for electrodes and contact arms.Watch for: Heat treated; give the condition on the drawing.
Finish for the contact face
- Silver
- The lowest contact resistance, for bolted and plug-in joints.Watch for: Tarnishes in storage; ask for anti-tarnish where parts wait.
- Tin
- Low cost and good for bolted joints.Watch for: Not for sliding or high-cycle contacts.
- Nickel
- A hard, corrosion-resistant layer, alone or under silver.Watch for: Higher contact resistance than silver or tin.
Specifications
- Types
- Terminal studs and pins, connector bodies and sockets, machined terminals and blocks, contact arms and fingers, welding electrodes, cold plates and heat spreaders
- Materials
- ETP copper C11000; oxygen-free C10200 and C10100; tellurium copper C14500; copper chromium zirconium C18150
- Processes
- CNC turning, sliding-head turning, CNC milling, drilling and tapping
- Bar diameter
- 3–80 mm standard; larger on review
- Tolerances
- To your drawing; ±0.01 mm on critical features on review
- Threads
- Metric ISO, UNC, UNF; gauged go and no-go to 6g and 6H
- Plating
- Silver, tin and nickel
- Checks
- Critical dimensions and GD&T; thread gauge; surface finish; plating thickness; material grade
- Quantities
- Prototype builds to mass production
Copper grades compared
Tellurium copper machines four times faster than pure copper and gives up little conductivity.
ETP copperOxygen-freeTellurium copperCopper chromium zirconium
Typical values from Copper Development Association alloy data. Machinability against free-cutting brass C36000 at 100.
Electrical conductivity
ETP, 100% IACS
Oxygen-free, 100% IACS
Tellurium, about 93% IACS
CuCrZr, about 80% IACS
Machinability
ETP, 20
Oxygen-free, 20
Tellurium, 85
CuCrZr, 20
Questions buyers ask
Why is pure copper hard to machine?+
Pure copper is soft and gummy. It clings to the tool, leaves burrs and tears the surface. Tellurium copper machines far more cleanly where the drawing has fine threads or many features.
Which copper should I use for a brazed part?+
Oxygen-free copper. ETP copper contains a little oxygen, which can cause embrittlement when it is brazed or welded in a hydrogen-bearing atmosphere.
Do you gauge every thread?+
Threads are checked with go and no-go gauges to the class on your drawing, after plating, because plating changes the fit.
Silver or tin plating?+
Silver gives the lowest contact resistance and suits plug-in and high-current joints. Tin costs less and suits bolted joints. Give the thickness on the drawing.
How is the copper price handled?+
The quotation states the metal price and the date it is based on, so you can see how much of the price is metal and how much is the work.
Can you match an existing part from another supplier?+
Yes. Send the drawing, and a sample if the drawing is incomplete. We tell you what can be held before we quote, then make samples for your approval.
Can you take a small order?+
Yes. Small, engineering-heavy batches are work we take, from prototype quantities upwards.
Send the drawing
Email us your enquiry at contact@qumek.com. We respond within 12 hrs.
Your enquiries are confidential with us and we proceed with manufacturing only after signing a NDA.
Need a DFM review, a prototype or a test plan before production? See the services.