Copper Machine Screws

Copper Machine Screws

Pricing: US$ 15.80 / Kilogram (FOB India | MOQ: 25 Kg | All head types and thread types available)

Electrical Accessories India manufactures and exports copper machine screws in all standard head types and thread types, conforming to DIN 84, DIN 963, DIN 965, DIN 966, ISO 1207, ISO 2009, ISO 2010, ISO 7045, and ASME B18.6.3 standards. Produced from high-conductivity copper grades C11000 (ETP), C10100 (OFHC), C12200 (DHP), and C14500 (tellurium copper), these copper fasteners are specified for electrical panel wiring, switchgear component assembly, earthing terminal assembly, PCB standoff fastening, relay mounting, metering equipment, bus-bar joint bolting, transformer terminal connection, and precision instrument assembly. With inherent electrical conductivity exceeding 98% IACS, corrosion resistance, and non-magnetic properties, copper machine screws are the fastener of choice for electrical OEMs, EPC contractors, power utilities, and precision instrument manufacturers worldwide.

Product Overview – Copper Machine Screws

Copper machine screws—also referenced in global procurement as copper set screws, copper instrument screws, copper panel screws, copper binding screws, copper electrical fasteners, copper thread-forming screws, copper self-tapping screws (in brass/copper tapped holes), copper socket screws, copper cap screws, copper Allen head screws, copper Torx screws, and copper Phillips screws—represent a broad family of threaded copper fasteners used in assemblies where the mating part contains a pre-tapped or self-tapped hole. Unlike bolts (which use a nut), machine screws thread directly into a tapped hole or a weld nut, making them essential for panel assembly, equipment mounting, and precision electrical instrument fastening.

Pan Head Copper Machine Screws

Pan head copper machine screws (DIN 7985, ISO 7045) feature a low-profile rounded head with a large bearing surface that distributes clamping load over a wide area, reducing pull-through in thin sheet metal panels, terminal blocks, and PCB mounting applications. Drive types: Phillips (DIN 7985), slotted (DIN 84 equivalent for pan head), Pozidriv (ISO 7045), and combination (slotted-Phillips). Standard sizes: M1.6 to M12 (metric), #2 to 3/8 (imperial). The pan head profile is the most common head type in electrical panel assembly, relay mounting bases, cable management clips, DIN rail accessory mounting, and contractor panel wiring systems. Copper pan head machine screws are specified per IEC 60947 switchgear standards where non-ferrous fasteners are required to prevent magnetic interference with electronic relays and current transformers.

Flat/Countersunk Head Copper Machine Screws

Countersunk copper machine screws (DIN 963 slotted, DIN 965 Phillips, ISO 2009 slotted, ISO 7046 Phillips) have an 82° or 90° conical head that seats flush with or below the mating surface when installed in a countersunk hole. This flush-mount characteristic is required in bus-bar top cover panels, electrical enclosure door fastening, earth plate mounting, and precision metering instrument covers where protruding fastener heads are not acceptable. Oval/raised countersunk variants (DIN 966, ISO 2010) are used where a decorative finished appearance is needed while maintaining countersink seating. Standard sizes: M2 to M12 (metric); #2 to 3/8″ (imperial). Material: C14500 tellurium copper is preferred for countersunk screws requiring tight head angle tolerances, due to its superior machinability (index 85%).

Round Head Copper Machine Screws

Round head copper machine screws (DIN 84, ISO 1207) feature a high-profile domed head with a slotted drive. They provide excellent mechanical drive capability and visual indication of screw position in terminal strip assemblies, relay socket mounting, and instrument panel wiring. Standard sizes: M1.6 to M10. Round head machine screws are specified in IEC 60669 switch assembly, IEC 60947 contactor terminal connections, and traditional panel wiring applications where Phillips drive is not required. In older electrical standards (BS 1981, DIN 84), round head slotted screws are the default fastener for terminal block rail mounting and cable lug clamp bolts.

Fillister Head and Cheese Head Copper Machine Screws

Fillister head copper machine screws (DIN 84 cheese head, ASME B18.6.3 fillister head) feature a cylindrical head with a deep slotted or Phillips drive recess, providing maximum driver engagement and torque transmission in deep counterbored holes. Cheese head screws (DIN 84) are the European standard equivalent, widely used in switchgear component mounting, high-torque terminal assembly, and current transformer (CT) secondary circuit terminal screws. Fillister head is the US/ASME equivalent, specified in ANSI/UL listed electrical equipment. Standard sizes: M2 to M12 (metric); #2 to 1/2″ (imperial). The deep drive recess makes these screws particularly suitable for power tools and automated assembly in high-volume electrical OEM production lines.

Hex Head and Hex Socket (Allen) Copper Machine Screws

Hex head copper machine screws (DIN 933/ISO 4017 equivalent but in small sizes M3–M12) are used where a wrench or spanner is the preferred tool, particularly in high-torque bus-bar joint assembly, transformer terminal clamping, and cable tray ground bonding. Hex socket (Allen/internal hex) copper cap screws (DIN 912, ISO 4762) are used where a flush or recessed head is needed with high torque capability: switchgear component mounting, GIS spacer fastening, precision instrument assembly, and EMI shielding cover fastening. Socket button head (DIN 9427, ISO 7380) provides a lower-profile alternative for space-constrained assemblies. Allen key drive ensures higher torque without cam-out, critical in copper’s softer material properties.

Truss Head and Other Specialty Head Copper Machine Screws

Truss head copper machine screws feature an extra-large diameter, low-profile dome head that provides an even larger bearing area than pan head, ideal for oversized holes in sheet metal, plastic panels, and composite materials. They are specified for cable management clip fastening in electrical enclosures, DIN rail cover fastening, and thin-wall conduit fitting assembly. Other specialty head types produced include: binding head (for wire terminal connections in older telecoms and power equipment), bugle head (for self-tapping in drywall/composite panels), flange head (built-in washer for load distribution), and shoulder head (for precise pivot point fastening in relay mechanisms and electrical switch assemblies).

Thread Types – Metric and Imperial

All copper machine screws are produced in the following thread systems: metric coarse (DIN 13, ISO 68-1): M1.6×0.35 through M12×1.75 – the global standard for electrical and industrial OEM equipment; metric fine thread (DIN 13, ISO 724): M4×0.5 through M12×1.0 – used in precision instruments and vibration-resistant electrical assemblies; Unified National Coarse (UNC, ASME B1.1): #2-56 through 1/2-13 – for USA, Canada, and ASME-standard electrical equipment; Unified National Fine (UNF, ASME B1.1): #2-64 through 1/2-20 – for precision US-standard assemblies; British Standard Whitworth (BSW, BS 84): 1/8″ to 1/2″ – for legacy UK and Commonwealth electrical equipment; British Association (BA, BS 57): 0BA to 10BA – for miniature screws in meters, instruments, and relay contacts; and Unified Extra Fine (UNEF) and metric extra fine on custom request.

Drive Recess Types

Copper machine screws are produced in all standard drive types: slotted (DIN 84/963/965 equivalent) – the most basic, suitable for manual assembly in terminal connections; Phillips (Type II, DIN 7985/ISO 7045) – high-volume assembly with power screwdrivers; Pozidriv (Type Z, ISO 4757) – improved cam-out resistance over Phillips, popular in European electrical OEM assembly; Torx (Type TX, ISO 10664) – six-lobe drive with maximum torque transmission and zero cam-out, specified for high-torque automated assembly; hexagon socket/Allen (DIN 912/ISO 4762) – maximum torque capability; square/Robertson drive – used in North American electrical panels; combination (dual-drive, e.g., slotted-Phillips) – for field serviceability.

Key Features

• All head types: pan, round, flat/countersunk, oval, fillister, cheese, hex, hex socket, truss, binding, flange
• All thread types: metric coarse/fine, UNC, UNF, BSW, BA, UNEF
• All drive types: slotted, Phillips, Pozidriv, Torx, Allen/hex socket, square, combination
• Electrical conductivity: ≥98% IACS (C11000) to ≥100% IACS (C10100)
• Size range: M1.6 to M12 (metric); #0 to 1/2″ (imperial)
• Non-magnetic: ideal for use near CTs, electronic relays, and sensitive instruments
• RoHS 2 and REACH compliant copper alloys and surface treatments
• EN 10204 3.1 material test certificates available

Electrical Conductivity and Non-Magnetic Properties

Copper machine screws in C11000 (ETP) grade provide ≥98% IACS electrical conductivity—approximately 6× better than 304 stainless steel fasteners—making them essential where the fastener is part of the electrical circuit, such as in terminal connection screws, bus-bar joint bolts, grounding stud assembly, and earthing system connections. Copper’s non-magnetic permeability (μr ≈ 1.0) means copper machine screws do not distort the magnetic field of current transformers (CTs), electronic energy meters, or sensitive relay coils. This non-magnetic property is specifically required in IEC 62053 (electricity metering equipment), IEC 61869 (instrument transformer standards), and DIN VDE 0100 terminal connection specifications where steel fasteners would introduce ferromagnetic interference.

Anti-Galling and Corrosion Resistance

Copper-to-copper threaded connections have inherent lubricity (copper’s coefficient of friction against copper: 0.6 dry, 0.3 with cutting fluid) that prevents galling and thread seizure, unlike stainless steel or titanium screw-to-copper-insert combinations that frequently gall. Copper machine screws into copper tapped holes, copper insert nuts, and copper stud-mounted terminals are specified for applications requiring repeated assembly/disassembly: electrical relay replacement, meter terminal maintenance, transformer tap changer servicing, and distribution board circuit breaker replacement. Corrosion resistance: C11000 and C12200 copper withstand atmospheric, seawater, and mild acid environments without significant corrosion, qualifying for coastal, marine, and tropical electrical installations.

RoHS and REACH Compliance

All copper machine screw alloys and surface treatments conform to RoHS 2 Directive (2011/65/EU) Annex II (maximum concentration values: Pb ≤ 0.1%, Cd ≤ 0.01%, Hg ≤ 0.1%, Cr(VI) ≤ 0.1%, PBB ≤ 0.1%, PBDE ≤ 0.1%, DEHP ≤ 0.1%, BBP ≤ 0.1%, DBP ≤ 0.1%, DIBP ≤ 0.1%) and REACH SVHC candidate list. Compliance declarations and substance data sheets (SDS) are provided with each shipment. ELV Directive compliance (2000/53/EC) is also declared for automotive electrical applications. This ensures global export compliance for customers shipping final products to EU, UK, USA, and Australian markets.

Surface Finish Options for Copper Machine Screws

Available surface treatments: bright copper (as-machined, no coating); chemical passivation (bright dip, acid cleaning); tin plating (ASTM B545, 2–5 μm, for corrosion protection and reduced contact resistance in tropical environments); silver plating (ASTM B700, 3–8 μm, for instrument and precision electrical assembly where contact tarnishing is unacceptable); nickel plating (ASTM B689, 3–5 μm, for harsh chemical environments); gold plating (ASTM B488, 0.5–1 μm, for precision connector and electronic assembly); and organic lacquer/varnish for temporary corrosion protection during transit and storage. All plating is RoHS 2 compliant; plating thickness verified by XRF (ASTM B568).

Manufacturing Quality and Inspection

Copper machine screws are manufactured on multi-spindle screw machines (Davenport, Wickman, Index) and CNC single-spindle automatics to ensure thread accuracy, head form precision, and drive recess quality. Thread accuracy is verified with GO/NO-GO gauges (ISO 965-1 class 6g for external threads) calibrated to NABL-accredited standards. Head form dimensions are checked per DIN/ISO standard tables using calibrated digital micrometer and CMM. Drive recess depth and width are verified to DIN/ISO tolerance limits. AQL 1.0 sampling inspection (ISO 2859-1) is performed on each production lot. 100% visual inspection ensures zero burr, no head cracks, and correct drive recess form.

Technical Specifications

Copper Raw Material Grades and International Equivalents

Product Types and Variants

Applications by Industry

Manufacturing Process

Copper machine screws are manufactured using a combination of cold heading and CNC screw machining processes. (1) Raw Material Incoming Inspection: copper wire (for cold heading, sizes M1.6–M6) or copper rod (for screw machine, sizes M5–M12) is tested for composition, conductivity, and hardness. (2) Cold Heading (small sizes M1.6–M6): wire is cut and cold-headed in one or two blows to form the head shape; drive recess is formed simultaneously using punch tooling. Thread is rolled by CNC thread rollers. (3) CNC Screw Machining (M5–M12): copper rod is machined on multi-spindle screw machines or CNC turning centres; head is turned, drive recess is milled or broached, and thread is cut or rolled in sequence. (4) Drive Recess Formation: Phillips/Pozidriv/Torx recesses are punched in cold heading or milled in CNC machining; slotted recesses are milled with carbide slitting saws. (5) Thread Rolling / Thread Cutting: CNC thread rolling produces stronger, work-hardened threads; thread cutting is used for fine pitch and BA threads. (6) Deburring and Inspection: barrel tumbling removes micro-burrs; 100% visual inspection and AQL 1.0 dimensional sampling. (7) Surface Treatment: electroplating per customer specification. (8) Packing and Documentation: count-bags, cartons, MTCs, compliance declarations.

Quality Standards and Certifications

Why Choose Electrical Accessories India for Copper Machine Screws?

Electrical Accessories India is a specialist copper fastener manufacturer offering the most comprehensive range of copper machine screw head types, thread types, and drive options under one roof. Our facility operates dedicated copper cold headers, multi-spindle screw machines, CNC thread rollers, and in-house electroplating lines. We provide: US$ 15.80/kg FOB India competitive pricing; delivery in 2–4 weeks for standard orders; EN 10204 3.1 material test certificates; AQL 1.0 inspection with full dimensional reports; RoHS/REACH compliance declarations; ISPM-15 export packaging; and custom engineering for special drive, thread, and head combinations against OEM drawings. Export documentation capability for all major trade lanes: India to USA, UK, Germany, France, Italy, Spain, UAE, Australia, Singapore, South Africa, Brazil, and Canada.

Frequently Asked Questions (FAQ)

Q1. What head types of copper machine screws do you manufacture?

We manufacture all standard head types: pan head, round head, flat/countersunk head, oval/raised countersunk head, fillister head, cheese head, hex head, hex socket/Allen head, truss head, binding head, bugle head, and flange head. Custom non-standard head profiles are produced against customer CAD drawings. All head dimensions conform to applicable DIN/ISO/ASME standards.

Q2. What thread standards are available for copper machine screws?

We produce copper machine screws in: metric coarse (DIN 13/ISO 68-1, M1.6–M12); metric fine (DIN 13, M4–M12); Unified National Coarse (UNC, ASME B1.1, #0-80 to 1/2-13); Unified National Fine (UNF, ASME B1.1, #0-80 to 1/2-28); British Standard Whitworth (BSW, BS 84, 1/8″–1/2″); British Association (BA, BS 57, 0BA–10BA); and Unified Extra Fine (UNEF) on request. Custom thread pitches can be produced against drawing.

Q3. Which copper grade is recommended for electronic instrument screws?

C14500 (tellurium copper) is recommended for small machine screws (M1.6–M5) used in precision instruments, relay assemblies, and electronic equipment due to its machinability index of 85–90%, which enables sharp drive recess formation and clean thread cutting without burrs. C11000 ETP copper is the standard choice for M4–M12 electrical panel screws. For non-magnetic CT secondary circuit screws in metering panels, C10100 OFHC is specified.

Q4. Can you produce BA thread copper machine screws for vintage/legacy electrical equipment?

Yes. We produce British Association (BA) thread copper machine screws from 0BA to 10BA in round head (BS 57 slotted) and pan head (Phillips) configurations. These are used for legacy UK railway signalling equipment, vintage instrument repair, power plant control panel restoration, and heritage electrical installations. Minimum order quantity for BA thread variants is 25 kg.

Q5. What is the tensile strength of copper machine screws?

C11000 ETP copper machine screws (annealed): 200–250 MPa tensile, 40–60 HV hardness. C11000 half-hard: 280–350 MPa tensile, 80–95 HV. C14500 tellurium copper: 250–300 MPa tensile, 70–85 HV. For high-strength applications requiring >400 MPa, C17200 beryllium copper (aged) can be specified; please consult our technical team for suitability.

Q6. Are copper machine screws available in self-tapping or thread-forming variants?

Yes. Copper thread-forming (Type F, DIN 7500) screws that form a thread in copper or brass holes by cold displacement are produced in pan, flat, and hex head with Phillips or Torx drive. These eliminate tapping operations in assembly and are specified for thin-wall copper terminal blocks, copper bus-bar accessory mounting, and copper sheet panel assembly where a tapped thread is not cost-effective to machine.

Q7. What is the minimum order quantity for copper machine screws?

Standard MOQ: 25 kg for catalogue sizes in C11000 ETP copper. For special thread systems (BA, UNEF), non-standard alloys (C10100, C14500), or custom head/drive combinations, MOQ is 50 kg. Sample orders of 0.5–2 kg are accepted at nominal sample charge for OEM qualification and type testing.

Q8. What packaging options are available for copper machine screws?

Standard packing: polybag (VCI-treated) in count quantities (e.g., 500 pieces/bag), inner carton with part label, outer corrugated carton. Bulk packing (per kg, loose) for automated assembly customers. Customer-specified packaging (e.g., sequenced bags, magnetic tape, tray packing for SMT assembly feeders) is available on request. All export packing complies with ISPM-15 phytosanitary standards.

Multilingual Equivalent Terms

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Request a Quote – Copper Machine Screws

Electrical Accessories India | Manufacturer & Exporter of Copper Machine Screws – All Head Types, All Thread Types
Email: info@elecaccs.com | Website: elecaccs.com
Price: US$ 15.80 / Kilogram (FOB India)
Lead Time: 2–4 weeks | MOQ: 25 Kg | All head types, thread types, and drive options available

Submit your drawing, specification, or head type/thread type combination to receive a detailed technical quotation within 24 business hours.