Solid contact rivets
One-piece rivets in silver alloy, headed for riveting into a carrier or spring.
For relays, switches and auxiliary contacts
Custom electrical contacts, made to your drawing.
Contact rivets, tips and contact assemblies in silver alloys on copper and brass carriers. Manufactured in India, brazed or welded and inspected against your drawing, and delivered to your Incoterm.
- Silver alloy to your grade
- Weld shear tested
- Measured records
Contact assembly, AgSnO₂ 88/12 tipDWG REV. B
- Contact material
- AgSnO₂ 88/12
- Carrier
- ETP copper C11000
- Critical dimension
- Tip height 1.50 ±0.05 mm
- Inspection
- Silver content and weld shear
What we make
Bimetal and trimetal rivets
A silver alloy face on a copper shank, so the silver goes only where the contact is made.
For relays and switches, at lower silver cost
Contact tips
Tips cut from strip or pressed and sintered from powder, ready for brazing or welding.
For contactors, MCBs and MCCBs
Contact assemblies
Tips brazed, welded or riveted onto copper or brass carriers, delivered ready to fit.
For breakers, contactors and switch-disconnectors
Inlay and clad strip
Silver alloy rolled into or onto copper strip, ready for your stamping line.
For high-volume stamped contacts
Arcing contacts
Silver tungsten, silver tungsten carbide and copper tungsten contacts for heavy arcing.
For ACBs, MCCBs and load-break switches
Choosing a contact
The arc your device makes decides the alloy. The carrier and the volume decide how it is joined.
Contact material for the duty
- Fine silver Ag
- The highest conductivity, for low currents and signal contacts.Watch for: Welds and erodes under heavy arcing.
- Silver nickel AgNi10, AgNi15
- Good erosion resistance and easy to form, for relays and auxiliary contacts.Watch for: Limited weld resistance at high inrush currents.
- Silver tin oxide AgSnO₂
- Resists welding and erosion at high inrush, for contactors and MCBs.Watch for: Higher contact resistance than silver nickel; give the oxide content and additive.
- Silver graphite AgC
- Will not weld under short-circuit current, for breaker contacts paired with a harder face.Watch for: Erodes quickly on its own; it is used as one half of a pair.
- Silver tungsten and copper tungsten AgW, AgWC, CuW
- Hard and arc resistant, for arcing contacts in MCCBs, ACBs and load-break switches.Watch for: Brittle, so it is brazed, not riveted.
- Silver cadmium oxide AgCdO
- Found on older drawings. Cadmium is restricted under RoHS, and silver tin oxide is the usual replacement.Watch for: Confirm whether an exemption applies to your product before reordering.
Joining for the carrier
- Riveted
- The rivet is staked into the carrier with no heat.Watch for: A loose rivet raises contact resistance; check for movement.
- Brazed
- Silver brazing alloy joins the tip across its whole face.Watch for: Voids in the braze run hot; ask for coverage and shear results.
- Resistance welded
- Fast and clean, for high volumes.Watch for: Weld shear must be tested every batch.
Specifications
- Types
- Solid, bimetal and trimetal rivets; contact tips; brazed, welded and riveted contact assemblies; inlay and clad strip; arcing contacts
- Contact materials
- Ag; AgNi10, AgNi15; AgSnO₂ 88/12 and 90/10; AgZnO; AgC; AgW, AgWC; CuW; AgCdO only where an exemption applies
- Carrier materials
- ETP copper C11000; brass; phosphor bronze; copper chromium
- Rivet head diameter
- 2–10 mm standard
- Tip thickness
- 0.5–4 mm standard
- Joining
- Riveting, brazing, resistance welding
- Checks
- Silver content and grade certified; weld or braze shear; tip position and height; braze coverage where specified
- Standards
- Grade and silver content to your specification; dimensions to your drawing
- Quantities
- Prototype builds to mass production
Which silver alloy
No alloy wins on everything. Choose for the arc your device makes, then test it in the device.
Relative ratings for guidance, from published contact material data. Your device test decides the grade.
Fine silver, Ag
Low, steady contact resistance at small currents.
Conductivity
3 / 3
Weld resistance
1 / 3
Erosion resistance
1 / 3
Silver nickel, AgNi
Easy to form and rivet. Relays and auxiliary contacts.
Conductivity
3 / 3
Weld resistance
1 / 3
Erosion resistance
2 / 3
Silver tin oxide, AgSnO₂
High inrush and motor loads. Contactors and MCBs.
Conductivity
2 / 3
Weld resistance
3 / 3
Erosion resistance
3 / 3
Silver graphite, AgC
Will not weld under fault current. Paired with a harder contact in breakers.
Conductivity
2 / 3
Weld resistance
3 / 3
Erosion resistance
1 / 3
Silver tungsten, AgW
Heavy arcing and fault breaking. MCCBs and ACBs.
Conductivity
1 / 3
Weld resistance
3 / 3
Erosion resistance
3 / 3
| Material | Conductivity | Weld resistance | Erosion resistance |
|---|---|---|---|
| Fine silver, AgLow, steady contact resistance at small currents. | 3 / 3 | 1 / 3 | 1 / 3 |
| Silver nickel, AgNiEasy to form and rivet. Relays and auxiliary contacts. | 3 / 3 | 1 / 3 | 2 / 3 |
| Silver tin oxide, AgSnO₂High inrush and motor loads. Contactors and MCBs. | 2 / 3 | 3 / 3 | 3 / 3 |
| Silver graphite, AgCWill not weld under fault current. Paired with a harder contact in breakers. | 2 / 3 | 3 / 3 | 1 / 3 |
| Silver tungsten, AgWHeavy arcing and fault breaking. MCCBs and ACBs. | 1 / 3 | 3 / 3 | 3 / 3 |
Questions buyers ask
What is an electrical contact rivet?+
A small rivet with a silver alloy face that makes and breaks the circuit in a relay, switch or contactor. Solid rivets are silver alloy throughout. Bimetal rivets put the silver only on the face, on a copper shank.
What replaces silver cadmium oxide?+
Silver tin oxide, AgSnO₂, is the usual replacement, because cadmium is restricted under RoHS. The oxide content and additive are chosen for your device, and the device must be retested after the change.
How is the silver price handled?+
The quotation states the silver price and the date it is based on, and shows the work separately. You see exactly how much of the price is metal.
What do you check on every batch?+
Silver content and grade, certified on the batch record; weld or braze shear; and tip position and height against your drawing.
Bimetal or solid rivet: which do I need?+
A bimetal rivet uses less silver for the same contact face and costs less. A solid rivet suits small heads, high cycle counts, or designs where the shank also carries the arc.
Can you match an existing contact 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.