Brass Industry Glossary

A

ACS

Attestation de Conformité Sanitaire — French drinking-water certification. Mandatory for products in contact with potable water sold in France. Issued by accredited French test labs.

Admiralty brass (C44300)

~70% Cu, 29% Zn, 1% Sn, plus a trace of arsenic. Standard alloy for condenser tubes and seawater heat exchangers.

Almen strip

Steel strip used to measure shot-peening intensity per SAE J442/443.

Aluminium brass (C68700)

~77% Cu, 21% Zn, 2% Al. Used in marine condensers — the aluminium forms a protective passive layer.

Ammonia vapour test

Standard test for SCC susceptibility per ASTM B858.

Annealing

Heat treatment that softens cold-worked brass. Typical 350–600°C depending on temper target.

Arsenic-inhibited brass

Brass with 0.02–0.15% arsenic added to suppress dezincification. CW602N is the prototypical alloy.

ASTM B16 / B124 / B283 / B371

US specifications for brass rod, forging stock, drawn rod, and silicon brass respectively. See Standards Guide.

Across flats (A/F)

The distance between two opposite parallel flats of a hex feature. The "s" dimension on a hex nut drawing.

B

Barrel plating

Plating process where small parts tumble in a perforated barrel rotating through the bath. See surface finishes.

BSP / BSPP

British Standard Pipe Parallel — ISO 228. Cylindrical pipe thread with 55° profile, seals at the face on a washer or O-ring. The "G" designation.

BSPT

British Standard Pipe Tapered — ISO 7. Same profile as BSPP but 1:16 taper, seals on the thread flank. The "R" designation.

BTA (benzotriazole)

Organic corrosion inhibitor that forms a self-assembled molecular film on copper alloys. RoHS-compliant alternative to chromate passivation.

C

CAB / Cu-DLP / CDA

Copper Development Association — the US trade body that publishes the canonical UNS copper alloy database.

Cap nut (acorn nut)

Hex nut with a closed dome on one end. DIN 917 (low form) or DIN 1587 (high / acorn form).

CE marking

EU conformity marking. For brass fittings: required if under PED 2014/68/EU (pressure equipment), GAR 2016/426 (gas), or CPR 305/2011 (construction).

CMRT

Conflict Minerals Reporting Template. RMI (Responsible Minerals Initiative) form documenting 3TG smelter/refiner sourcing for Dodd-Frank §1502.

Compression fitting

Brass fitting that seals on an olive (ferrule) compressed onto the tube as the nut is tightened.

Copper Development Association (CDA)

Trade body publishing free technical bulletins on copper and brass alloys. copper.org

CuZn40Pb2

Brass with ~58% Cu, 2% Pb, balance Zn. The chemical-symbol equivalent of CW617N.

CW prefix

EN nomenclature for wrought copper alloys. CW = copper wrought. Followed by 3-digit number + letter (L = lead-free, N = standard, R = silicon).

Cu-ETP (C11000)

Electrolytic tough pitch copper. 99.90% Cu min, 100% IACS conductivity. The standard electrical copper.

D

Dezincification (DZ / DZR)

Selective corrosion mode where zinc dissolves out of brass under aggressive water conditions, leaving porous copper. "DZR" = Dezincification Resistant alloy. See Corrosion Guide.

DIN

Deutsches Institut für Normung — the German national standards body.

DIN 934 / ISO 4032

The standard hex nut. Most common nut on European drawings.

DIN 16903

The standard for moulding inserts. Forms A through U cover hex/round body, with/without head, with/without anti-rotation slot.

DVGW

Deutsche Vereinigung des Gas- und Wasserfaches — the German gas/water trade body. DVGW certification (W 270, W 534) is required for plumbing products in Germany.

E

ECHA

European Chemicals Agency. Administers REACH. Publishes the SVHC candidate list.

EEE

Electrical and Electronic Equipment. The scope of EU RoHS Directive.

EN 10204 Type 2.1, 2.2, 3.1, 3.2

Material certificate types. 2.1 = declaration of conformance. 2.2 = non-specific test report. 3.1 = batch-specific test results signed by manufacturer's QC. 3.2 = third-party witnessed.

EN 12164

European standard for brass rod for free machining. Covers composition, dimensional tolerance, and mechanical properties. See tolerances guide.

EN 12420

European standard for hot-forged brass dimensional tolerances. Three classes F1, F2, F3.

EN 13828

European standard for manually operated brass ball valves in plumbing service.

Erosion-corrosion

Combined mechanical + chemical attack from high-velocity flow. Limited to ~1.5 m/s for hot water in copper alloy systems.

F

FAI

First Article Inspection. The first part off a new production run, inspected against every dimension on the drawing before bulk production proceeds. AS9102 is the standard template.

FOB

Free On Board (Incoterms 2020). Seller delivers goods to the port of shipment cleared for export. Buyer takes risk and cost from rail of the vessel.

Free-machining brass

Brass alloyed with 1.5–3.5% lead (CW617N, CW614N) to break chips and lubricate the cutting tool. CW614N is the 100% machinability reference standard.

G

G thread (BSPP)

BSP parallel thread designation. See Threads guide.

GAR

Gas Appliance Regulation 2016/426 (EU). Replaces the GAD directive. Mandatory CE for gas-burning appliances and fittings.

GD&T

Geometric Dimensioning and Tolerancing. ISO 1101 (Europe) and ASME Y14.5 (USA). The 14 symbols cover form, orientation, location and run-out.

Galvanic corrosion

Corrosion of the less-noble metal when two dissimilar metals are in electrical contact in an electrolyte. Brass-aluminium is the classic high-risk pairing.

GSTIN

Goods and Services Tax Identification Number. India's 15-digit tax identifier. Required on every export invoice.

H

Hex standoff

Hexagonal-bodied brass spacer with threaded ends — Male-Female, Female-Female or Male-Male. Common in PCB and enclosure hardware.

HS code

Harmonised System code. The 6-10-digit international commodity code used on customs declarations. Most brass fittings fall under HS 7415 (fasteners) or 7412 (fittings).

Hot forging

Forming brass at 650–820°C in a die under high pressure. Used for near-net-shape valve bodies and complex fittings. See manufacturing guide.

I

IACS

International Annealed Copper Standard. 100% IACS = the conductivity of pure annealed copper (~5.8 × 10⁷ S/m). Used to express electrical conductivity of alloys as a percentage.

IEC (Importer-Exporter Code)

India's 10-digit code from DGFT required to import or export from India.

Incoterms 2020

ICC's international commercial terms — EXW, FOB, CIF, DAP, DDP, etc. Defines who carries risk and cost at each step of an international shipment.

ISO

International Organization for Standardization, Geneva. Publisher of the global voluntary standards.

ISO 261 / ISO 965

General-purpose metric screw threads. M3, M4, M5, M6 etc.

ISO 4032

The international hex nut standard. DIN 934 is the corresponding German national standard.

ISO 6509-1

Dezincification test method — 1% CuCl₂, 75°C, 24h. Pass ≤ 200 µm DZ depth.

ISO 9001:2015

Quality management system standard. Brassland is ISO 9001, 14001 & 45001 certified by DQS Inc.

ISO 2768

General tolerances for linear, angular and geometric features. Classes f / m / c / v.

J

JIC fitting

SAE J514 hydraulic fitting with 37° flare cone seal. The standard US hydraulic fitting.

JIS

Japanese Industrial Standards. Japanese national standards body. JIS C3604 is the nearest JIS free-cutting grade to CW614N/C36000; the JIS grade for CW617N-type hot forging is C3771.

K

Kappa-phase (κ)

Cu-Zn-Si intermetallic phase in silicon brass (CW724R, C69300). Provides intrinsic dezincification resistance.

KIWA

Dutch certification body. KIWA-ATA approval is the Dutch drinking-water certification.

L

L-suffix alloys

EN alloy designation suffix meaning "low lead" or "lead-free" (CuZn37 = CW508L; CuZn42 = CW510L; CuZn40 = CW509L).

Lacquer (brass)

Clear protective coating on polished brass. Acrylic (Incralac) is the industry standard; cellulose nitrate is the cheaper alternative.

Lead-free brass

Brass with Pb ≤ 0.10% per RoHS. Includes CW724R, C6802, CuZn37 (CW508L), CW510L, C11000.

LME

London Metal Exchange. Sets the daily reference price for copper, zinc and lead. Brass price is roughly proportional to LME copper.

M

Machinability index

Relative ease of machining. CW614N = 100% reference. CW617N ≈ 90%, CW602N ≈ 65%, CW724R ≈ 80%, CuZn37 ≈ 30%, C11000 ≈ 20%.

MID 2014/32/EU

Measuring Instruments Directive. Covers water meters, gas meters, heat meters etc.

Mill certificate

Material certificate accompanying a brass shipment, documenting alloy composition, mechanical properties, and test results. See EN 10204.

MOQ

Minimum Order Quantity. Brassland's typical MOQ: 1,000–10,000 pieces for stock alloys; 500 pieces for custom-tooled parts.

Moulding insert

Brass insert designed to be moulded into a thermoplastic component at moulding time. DIN 16903 standardises 14 forms (A–U).

N

NPT

National Pipe Tapered. ASME B1.20.1. The standard US pipe thread, 60° profile, 1:16 taper. Not interchangeable with BSPT.

NPTF

NPT Dryseal. ASME B1.20.3. NPT geometry held to tighter tolerances so the joint seals without sealant.

NSF/ANSI 61

The North American drinking-water-contact standard. Required by all US states and Canadian provinces. NSF 372 defines "lead-free" as weighted-average Pb ≤ 0.25%.

N-suffix alloys

EN alloy designation suffix for standard composition with normal lead (CW617N, CW614N, CW602N).

O

OFHC copper (C10200)

Oxygen-Free High Conductivity copper. 99.95% Cu min. Used where brazing or hydrogen-rich atmosphere makes Cu-ETP (C11000) unsuitable.

ORFS

O-ring face seal fitting per SAE J1453. Highest-pressure US hydraulic fitting.

P

Patina

The natural greenish layer that forms on exposed copper and brass over years. Cosmetic only; protects the underlying metal.

Pb (lead)

Element added to free-machining brass (1.5–3.5%) to improve chip formation. RoHS-restricted at > 0.10%; covered by Exemption 6(c) until 30 June 2027.

PED 2014/68/EU

EU Pressure Equipment Directive. Applies to fittings > PN 0.5 bar working pressure.

PPAP

Production Part Approval Process — automotive industry's part qualification framework. AIAG 4th edition is current.

Press-fit insert

Brass insert with knurled body driven into a pre-formed plastic boss. Held by interference of the knurl into the soft plastic.

Q

QC (Quality Control)

The inspection function that verifies parts meet drawing specification before shipment.

Quench

Rapid cooling step in heat treatment, usually water or oil.

R

Ra (surface roughness)

Arithmetic mean roughness of a surface profile. ISO 4287. Brass CNC parts typically 0.4–1.6 µm Ra.

R thread (BSPT)

BSP tapered thread designation.

REACH

Registration, Evaluation, Authorisation and Restriction of Chemicals. EU Regulation 1907/2006. Article 33 requires SVHC notification when SVHC content > 0.1% w/w.

RFQ

Request for Quotation. The standard buyer document that initiates a manufacturer quote.

RoHS

EU Restriction of Hazardous Substances Directive 2011/65/EU. Lead in copper alloys (> 0.10%) is under Exemption 6(c), valid to 30 June 2027.

S

Salt-spray test (NSS)

Standard accelerated corrosion test per ISO 9227 / ASTM B117. Common ratings: 24, 48, 96, 240 hours.

SCC (Stress Corrosion Cracking)

Brittle cracking under combined tensile stress + corrosive environment. "Season cracking" is the historical name. Common in brass exposed to ammonia.

SDS

Safety Data Sheet. Required under REACH for hazardous substances. Brassland supplies an SDS with every alloy shipment.

Section view

Engineering drawing convention showing a part cut through a plane, exposing internal features.

Self-tapping insert

Brass insert with cutting flutes that taps its own thread as it's driven into a plastic component. Trisert and Tappex are common brand names.

Silicon brass

Brass alloyed with 2.7–4.5% silicon. Forms the kappa-phase that provides intrinsic dezincification resistance. Examples: CW724R, C69300.

Specific gravity / density (brass)

~8.4–8.5 g/cm³ for most leaded brass; ~8.5 for CW602N DZR; ~8.3 for silicon brass.

SVHC

Substance of Very High Concern. REACH candidate list. Lead is on the SVHC list since June 2018.

Swiss CNC

Sliding-headstock CNC turning, originally developed in Switzerland for watch parts. Achievable tolerance ± 0.005 mm, surface finish Ra 0.2 µm.

T

Temper (R360, R430, R600)

EN designation of cold-worked condition. The number is minimum tensile strength in MPa. R360 = soft/annealed; R600 = highly cold-worked.

Thread chasing

Re-running a die through a damaged or partially-formed thread to clean and recut it.

Trisert

Tappex brand name for self-tapping threaded inserts. Generic equivalents are sold under "Trisert-style" in industry trade.

U

UNS

Unified Numbering System for metals (USA). C-prefix numbers (C11000, C36000, C37700, etc.) are the UNS designations for copper alloys.

Underplate

An intermediate plating layer applied between the substrate and the top coat. Nickel underplate is standard for tin / silver / gold on brass.

V

Verdigris

The greenish copper carbonate / acetate that forms on weathered brass. Different from dezincification (which leaves white-pink copper residue).

Vibratory finishing

Mass finishing process where loose abrasive media tumbles with brass parts in a vibratory bowl. Used to deburr and homogenise the surface.

W

WRAS

Water Regulations Advisory Scheme (UK). Required approval for plumbing products sold for UK drinking water service.

WIP

Work-In-Progress. Brassland's MES tracks WIP per CNC machine.

X

X-ray fluorescence (XRF)

Non-destructive thickness gauge for plating layers. Common brand: Fischerscope.

Y

Yellow brass

Common-use term for high-zinc brass (~30–40% Zn). Includes CW617N, CW614N. So called for its characteristic yellow colour.

Yield strength (Rp0.2)

Stress at 0.2% permanent strain on a tensile test. For CW617N R360 ≥ 140 MPa; R430 ≥ 250 MPa.

Z

Zinc (Zn)

The principal alloying element in brass. Higher Zn → higher strength but higher dezincification risk. Risk threshold ~15% Zn.

Zinc-oxide / Zincite

White zinc oxide that can form on dezincified brass surfaces in aggressive water. A failure-mode indicator.

Frequently asked questions

Sources & references

Last reviewed: June 2026. Verify against the current published edition of any cited standard. General engineering reference only.

Last reviewed: June 2026. Cross-references and external links verified at time of writing. For procurement-critical decisions verify against the current published edition of the cited standards.