Brass Screw Machine Parts

Brass Screw Machine Parts

Brass screw machine parts — also known as brass automatic screw machine components, brass Swiss-type turned parts, brass multi-spindle automatic parts, or brass bar-turned components — are high-volume precision parts produced on single-spindle and multi-spindle automatic screw machines, Swiss-type CNC lathes, and cam-operated automatic lathes from free-cutting brass rod. Electrical Accessories India produces brass screw machine parts in CW614N (CuZn39Pb3), IS 319 Type 1, CW617N (CuZn40Pb2), and related alloys for electrical connectors, terminals, fasteners, contact pins, and instrumentation fittings supplied to OEMs in India, Europe, the USA, and the Middle East.

Product Overview

What Are Brass Screw Machine Parts?

Screw machine parts are components produced using automatic, cam-driven, or CNC-controlled screw machines and bar-fed turning machines that can perform multiple simultaneous operations — turning, boring, drilling, threading, cross-drilling, and grooving — in a single setup cycle. The term “screw machine parts” covers a wide range of turned components including screws, pins, sleeves, bushings, inserts, studs, and connector bodies. Free-cutting brass (CW614N, IS 319) is the ideal material due to its excellent chip formation, high surface finish, and machinability index of 100. Screw machine parts are produced in volumes from 10,000 to 10 million pieces per production run.

Automatic Screw Machine Process

Automatic screw machines use collet-fed bar stock and multiple tool slides to machine components without manual intervention between cycles. Single-spindle automatics (Brown & Sharpe type, Citizen, Tornos, Traub) are used for complex geometries with long cycle times. Multi-spindle automatic screw machines (Wickman, Index, Davenport) turn 4–8 parts simultaneously, dramatically increasing output. Swiss-type CNC lathes (Citizen, Star, Tsugami) are used for slender, long-length components requiring tight tolerances and high surface finish. Electrical Accessories India operates a mix of these platforms to match output rate and precision requirements for each component type.

Alloy Properties for Screw Machining

CW614N (CuZn39Pb3, IS 319 Type 1) is the first-choice alloy for brass screw machine parts. It contains 2.5–3.5% lead which acts as a chip-breaker, creating short, broken chips that evacuate the cutting zone cleanly at high speeds. This enables cutting speeds of 200–350 m/min and tool lives of millions of components without regrinding. Where dezincification resistance is required (potable water, marine, gas), CW602N (CuZn36Pb2As) is substituted. For higher strength forged/pressed applications, CW617N (CuZn40Pb2) is used. All alloys are procured as certified rod with MTRs from ISO-accredited mills.

Component Complexity and Size Range

Brass screw machine parts range from simple reduced-OD pins 2 mm in diameter to complex multi-stepped connector bodies 50 mm in diameter with internal bores, cross-holes, threads, and knurls. Electrical Accessories India handles components with up to 6 turning diameters, 4 drilled features, 2 tapped threads, and external knurl in a single machine cycle. Precision tolerances: ±0.01 mm on diameter, 6g/6H on threads, Ra 1.6 µm surface finish as-machined. Tighter tolerances achievable on secondary grinding operations.

Secondary Operations and Finishing

After screw machine production, parts may undergo secondary operations: deburring (vibratory, ultrasonic), tapping, reaming, slotting, milling of flats, thread rolling, and surface treatment. Finishing options include barrel polishing, electroplating (nickel, tin, chrome), electroless nickel plating, passivation, and anodizing (for aluminium inserts in brass assemblies). Sub-assembly and kitting services — combining brass machined parts with inserts, O-rings, or springs — are available for supply to production lines.

Quality Assurance and Traceability

Electrical Accessories India implements statistical process control (SPC) on high-volume screw machine runs. First-article inspection (FAI) is performed before each production run. In-process checks at every 500th piece (or per AQL plan) cover critical dimensions, thread gauging, and visual inspection. Final AQL inspection to ISO 2859 or customer-specified plan before shipment. Full batch traceability: raw material heat number → production machine ID → operator → QC sign-off → shipping lot.

Key Features

• High-volume production: up to 1 million+ pieces per month on multi-spindle automatics
• Alloys: CW614N (CuZn39Pb3), CW617N, CW602N, IS 319 — machinability index 100
• Dimensional tolerance: ±0.01 mm on turned diameter; 6g/6H threads per ISO 965
• Component size range: 2 mm to 50 mm OD; up to 200 mm length
• Swiss-type CNC lathes for slender precision parts (length-to-diameter ratio up to 20:1)
• Multi-spindle automatics for complex parts in 4–8 simultaneous cuts
• Secondary operations: cross-drilling, tapping, milling, slotting, knurling in-line
• Surface finish: Ra 0.8–3.2 µm as-machined; plating options available
• SPC (Statistical Process Control) on critical dimensions
• ISO 9001:2015 certified QMS; material traceability on every batch

Material Grades and International Equivalents

Technical Specifications

Product Types and Variants

Brass screw machine parts produced by Electrical Accessories India include: Contact pins and terminal pins for electrical connectors (M2.5–M12); Brass inserts and threaded inserts for plastic moulding (knurled OD, internally threaded); Brass studs and standoffs for PCB and panel mounting; Connector bodies and cable gland components machined from brass hex bar; Electrical terminal components — fork terminals, ring terminals, and flat pin terminals; Bushings, sleeves, and spacers for mechanical and electrical assemblies; Hollow bolts and banjo bolts for fluid-carrying applications; Custom screw machine parts to customer drawing for any OEM application.

Applications in Industry

Brass screw machine parts serve critical functions across multiple industries. In electrical and electronics, brass screw machine parts form the contacts, pins, and connector bodies in switchgear, motor control centres, distribution panels, and low-voltage wiring accessories. In telecommunications, brass turned parts are used for RF connector bodies, antenna fittings, and coaxial cable accessories. The automotive sector uses brass screw machine components for fuel injector parts, sensor housings, and pneumatic connectors. Instrumentation and process applications include flow meter bodies, pressure fitting adapters, and thermowell fittings. Plumbing and gas uses brass screw machine parts for valve stems, compression fitting bodies, and meter connectors.

Manufacturing Process

1. Drawing Review and DFM: Customer drawing reviewed for machinability, tolerance feasibility, and alloy suitability.
2. Raw Material: Certified brass rod received; OD tolerance and straightness verified; heat number logged.
3. Machine Setup: Cams or CNC program set up; tools set to drawing dimensions; trial parts produced.
4. First-Article Inspection: All dimensions checked against drawing; FAI report generated.
5. Production Run: Continuous monitoring; SPC on critical dimensions every 500 pieces.
6. In-Line Secondary Operations: Tapping, cross-drilling, knurling performed on same machine or transfer fixture.
7. Deburring: Vibratory deburring removes sharp edges; parts inspected for burr-free finish.
8. Final Inspection: AQL sampling; thread gauging; surface finish check; dimensional report.
9. Finishing: Plating, polishing, or passivation per specification.
10. Packing and Export: Component packing per customer spec; MTRs and CoC included.

Quality Standards and Certifications

Manufacturing compliance: ISO 9001:2015 QMS; EN 12164 for free-cutting brass rod (CW614N, CW602N); ASTM B16 for free-cutting brass rod and bar; IS 319 for Indian-standard brass; ISO 965 for metric thread tolerances; ISO 286 for dimensional tolerances; RoHS 2011/65/EU compliance (low-lead alloys available); REACH SVHC declarations available; ISO 2859 AQL inspection plans. Third-party audits by SGS, Bureau Veritas, or TÜV Rheinland on request.

Why Choose Electrical Accessories India

With over 30 years of manufacturing precision brass components in Jamnagar — the world’s largest brass parts manufacturing cluster — Electrical Accessories India offers unmatched combination of technical capability, quality, and competitive pricing. Our screw machine facility handles volumes from 1,000 to 10 million pieces with consistent dimensional quality. Dedicated quality engineers, in-house plating partnerships, and 30+ country export experience mean your brass screw machine parts arrive on time, on spec, and with full documentation. We support annual supply contracts, VMI programmes, and just-in-time delivery schedules.

Frequently Asked Questions (FAQ)

What is a brass screw machine part?

A brass screw machine part is a turned component produced on an automatic lathe (screw machine) from brass bar stock. The machine automatically feeds the bar, performs multiple simultaneous cutting operations, and parts off the finished component. The result is a high-volume, cost-effective precision brass component.

What grades of brass are used for screw machine parts?

The primary grade is CW614N (CuZn39Pb3, IS 319 Type 1) — free-cutting brass with 3% lead for excellent machinability. CW617N is used where higher strength is needed. CW602N is used for dezincification-resistant applications (gas, water). Low-lead alloys are available for RoHS compliance.

What is the typical production volume range?

Minimum order quantity is typically 5,000–10,000 pieces for screw machine parts. Volumes can range up to 10 million pieces per year for blanket order customers. High-volume multi-spindle production costs are significantly lower than single-spindle CNC production.

How do screw machine parts differ from CNC turned parts?

Screw machine parts are produced on cam-operated automatics optimised for high-volume, repeating production runs — fastest and most economical for high volumes. CNC turned parts are produced on programmable lathes better suited for complex geometries, small batches, and frequent design changes. For many components, both methods are viable; we advise the most cost-effective approach per quantity and complexity.

Can you hold ±0.01 mm tolerance on screw machine parts?

Yes. On CNC Swiss-type screw machines, ±0.005–0.01 mm on critical diameters is achievable with proper tooling, steady rest support, and in-process gauging. For cam-operated automatics, ±0.02–0.05 mm is typical for general dimensions, with tighter held on precision features.

What secondary operations can be performed?

In-line or post-process secondary operations include: cross-drilling, tapping (axial and radial), milling of flats, slotting, knurling, thread rolling, reaming, and assembly of inserts. Sub-assembly with O-rings, springs, or other components is also available.

Do you provide plating services?

Yes, through our established plating partners. Standard options: bright nickel, electroless nickel, tin plating, chrome, and passivation. Plating thickness certified by cross-section and XRF testing. Certificates per ASTM B733 (ENP) or ASTM B545 (tin) available.

What documentation is provided with shipments?

Standard documentation: commercial invoice, packing list, certificate of conformance, material test report (EN 10204 2.2 or 3.1), RoHS declaration, certificate of origin. First-article inspection report (FAIR) provided for new parts. Third-party inspection reports on request.

What is your sample lead time?

Prototype samples for new brass screw machine parts: 1–3 weeks from approved drawing. Production lead time after sample approval: 4–6 weeks for standard volumes. Rush production for established parts: 2–3 weeks subject to machine availability.

Equivalent Terms – Multilingual Reference

Related Products and Linked Terms

• Brass Parts – Brass CNC Machined Parts
• Brass Turned Parts – Brass Turned Components
• CZ121 Brass Turned Parts
• CW614N Brass Components and Parts
• CuZn39Pb3 Brass Parts and CuZn39Pb3 Components
• Copper Machined Parts

Request a Quote

Electrical Accessories India engineers are ready to review your drawing or specification and provide a detailed technical and commercial proposal within 24 hours. Send your RFQ with quantity, alloy grade, dimensional drawing (PDF/DXF/STEP), surface finish requirement, and delivery schedule. We export to 30+ countries with full shipping documentation.

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