Complete Datasheet: Stamped Electrical Terminals C360 Brass vs C110 Copper Properties
An engineer selected C360 brass for its machinability advantage in post-stamp threading, only to discover 40% contact force loss within six months as dezincification consumed the threaded interface in the humid outdoor cabinet.
In this datasheet, you will find tensile, conductivity, corrosion, and processing data for C36000 brass and C11000 copper side by side, each anchored in ASTM test methods.
Read the full comparison.
Mechanical & Physical Properties
C360 and C110 diverge across every property that matters to terminal design: tensile strength, conductivity, fatigue strength, and machinability. The selection decision hinges on whether current-carrying capacity or secondary machinability dominates the production requirement. For an overview of how alloy selection impacts tooling design, see progressive die tooling capabilities.
Tensile & Yield – C360 vs C110 Head-to-Head
C11000 in annealed condition delivers 220-250 MPa tensile with 70-110 MPa yield and 45% elongation. C36000 in half-hard condition reaches 340-470 MPa tensile with 230-310 MPa yield and 18-25% elongation. C360 is 40-50% stronger in yield, making it suitable for terminals requiring structural stiffness without a spring-beam function.
The yield strength advantage of C360 comes from lead particle dispersion (2.5-3.7% Pb per ASTM B16) that blocks dislocation glide. These same particles create the machinability benefit but act as crack initiation sites under cyclic loading.
C360 fatigue strength at 10^7 cycles (R = -1, ASTM E466) is 80 MPa versus C110 at 60 MPa — a much smaller 33% advantage than the 2-3x yield strength gap suggests. The yield-to-fatigue ratio disparity (3.9 for C360 versus 1.5 for C110) means C360’s strength advantage diminishes under cyclic loading above 10,000 cycles.
Elongation difference (45% for C110 versus 18-25% for C360) drives the forming limit. C110 accommodates a minimum bend radius of 0.5t. C360 requires 1.5t. Any terminal with bends below 1.5t must use C110. This is a common constraint in multi-bend contact beam terminals where the mechanical advantage of C360’s higher yield cannot compensate for its cracking risk at tight bend radii.
| Property | C11000 (Annealed) | C36000 (Half-Hard) |
|---|---|---|
| Tensile Strength | 220-250 MPa | 340-470 MPa |
| Yield Strength (0.2% offset) | 70-110 MPa | 230-310 MPa |
| Elongation at Break | 45% | 18-25% |
| Hardness | 45-55 HV | 110-150 HV |
| Elastic Modulus | 117 GPa | 105 GPa |
| Fatigue Strength 10^7 (R = -1) | 60 MPa | 80 MPa |
| Minimum Bend Radius | 0.5 t | 1.5 t |
All values at 23°C per ASTM E8 (tensile), ASTM E384 (hardness), and ASTM E466 (fatigue).
[Data Anchor]: C360 brass yield strength of 230-310 MPa exceeds C110 copper at 70-110 MPa by a factor of 2-3x. However, C360 fatigue strength of 80 MPa is only 33% higher than C110 at 60 MPa (both at R = -1, ASTM E466). The yield-to-fatigue ratio of 3.9 for C360 versus 1.5 for C110 means C360 cannot sustain its strength advantage under cyclic loading above 10,000 cycles.
Electrical Conductivity – Trade-off Magnitude
The defining difference between these two alloys is the 3.9x conductivity gap. C110 at 101% IACS versus C360 at 26% IACS determines the application domain. C110 is mandatory for any current-carrying terminal above 5 A. C360 is limited to mechanical grounding terminals, fuse clips, and non-current-carrying structural components.
Cold working after forming reduces C110 conductivity by 2-5% IACS (from 101% to a minimum of 96% IACS after 50% cold reduction). This derating occurs because plastic deformation introduces dislocation densities on the order of 10^12 to 10^14 lines per square metre. Each dislocation acts as a scattering center for conduction electrons.
The mean free path of electrons in high-purity copper (approximately 40 nm at room temperature) is reduced by a factor of 2-3 at these densities, directly increasing electrical resistivity. C360 drops from 26% to 23% IACS under the same degree of cold work — a smaller absolute drop but the same proportional reduction. At 100°C, C110 measures 95% IACS and C360 measures 24% IACS, maintaining the 3.9x ratio.
Contact resistance at the mating interface is governed by the bulk resistivity contribution plus the constriction resistance through the surface oxide film. A C110 terminal with 0.5 mm x 5 mm squared contact area contributes approximately 0.35 milliohm bulk resistance. The same geometry in C360 contributes 1.4 milliohm. In a circuit carrying 10 A, this 1.05 milliohm difference produces a 10.5 mW additional I-squared-R heating at the terminal, which raises the local temperature by an estimated 2-4°C depending on heat dissipation conditions.
[Data Anchor]: C110 copper at 101% IACS carries 3.9x the current of C360 brass at 26% IACS at equal cross-section. For a terminal carrying 10 A continuous current, C110 requires 1.0 mm squared cross-section to stay below a 30°C temperature rise. C360 requires 3.9 mm squared — a 290% larger terminal cross-section for the same current capacity. At 100°C, the ratio remains at 3.9 (95% IACS versus 24% IACS).
Machinability vs Functional Properties
C360 is the reference standard for free-cutting brass with a machinability rating of 100 (per CDPI standards). C110 rates at 20. This 5x difference drives the cost decision: if the terminal requires post-stamp drilling, threading, or turning operations, C360 reduces machining cycle time by 60-70% versus C110. C110 produces long, continuous chips that tangle in automated machining cells, causing 15-25% downtime for chip clearing. C360 produces short, broken chips that clear via coolant flow.
The trade-off: C360’s lead particles (2.5-3.7% Pb) create the chip-breaking property but introduce environmental restrictions. EU RoHS Exemption 6(c) and ELV Annex II Exemption 8c permit lead content up to 4.0 wt% in copper alloys.
However, leading automotive Tier-1 suppliers are increasingly enforcing internal lead-free specifications that reject C360 regardless of regulatory exemption, driven by end-of-life recycling concerns and the shift toward lead-free brass alternatives such as C46500 bismuth brass. C110 carries zero lead content and is universally compliant without exemptions.
[Data Anchor]: C360 brass machinability rating of 100 versus C110 copper at 20 drives a 60-70% reduction in secondary machining cycle time. However, C360 contains 2.5-3.7% Pb. While EU RoHS Exemption 6(c) and ELV Exemption 8c permit up to 4.0 wt% Pb in copper alloys, major automotive Tier-1 suppliers are enforcing internal lead-free specifications that effectively bar C360 from new terminal programs. C110 carries zero lead and is universally compliant.
Thermal & Environmental Limits
The thermal tolerance windows of C360 and C110 differ in direction and mechanism. C110 degrades through stress relaxation at moderate temperature. C360 degrades through lead-phase softening at grain boundaries in the 80-200°C range and dezincification in corrosive environments. These mechanisms set fundamentally different operating limits for the two alloys. For details on how material selection interacts with plating and finishing capabilities, see the finishing compatibility section below.
Temperature Resistance & Lead Content Constraints
Continuous operating temperature limits: C110 up to 100°C for spring-beam applications and 150°C for non-spring structural applications. C360 limited to 80°C continuous for any application because the lead phase (melting point 327°C) undergoes grain boundary softening above 80°C, reducing creep resistance. At 125°C, C360 loses 30% of hardness within 500 hours due to lead-phase coarsening and segregation at grain boundaries. C110 loses 15% of hardness at the same temperature and duration. This makes C360 unsuitable for engine-bay or under-hood connectors where ambient temperature exceeds 80°C.
In the 80-200°C range, C360’s hot shortness mechanism is lead-phase grain boundary softening and segregation, not melting. The lead particles (mp 327°C) remain solid but exhibit accelerated diffusion along grain boundaries at temperatures above 0.4 Tm (approximately 110°C for pure lead). This grain boundary lead enrichment reduces the cohesive strength of the interface and initiates intergranular stress corrosion cracking (IGSCC) under sustained tensile stress, particularly in atmospheres containing ammonia or amine compounds common in industrial control cabinet environments.
C110 maintains structural integrity up to 200°C for short-duration soldering or wave-soldering assembly without embrittlement risk. At 200°C, C110 retains 85% of room-temperature tensile after 100 hours of exposure. C360 at 200°C for the same duration shows 40% tensile loss due to grain boundary lead segregation.
[Data Anchor]: C360 brass continuous operating temperature is limited to 80°C. Above this threshold, lead-phase grain boundary softening reduces hardness by 30% within 500 hours at 125°C. In the 80-200°C range, the mechanism is lead-phase segregation at grain boundaries (not melting, mp 327°C), which reduces creep resistance and can initiate IGSCC in ammonia-containing atmospheres. C110 copper maintains structural integrity up to 150°C for non-spring applications and survives 200°C short-duration soldering with less than 15% tensile loss.
Corrosion Behavior – Galvanic & Atmospheric
Galvanic corrosion risk: both alloys form a significant anodic potential difference when mated with aluminum conductors. C110 measures 0.35 V versus SCE, and C360 measures 0.40 V versus SCE. The potential differences against aluminum (0.75 V versus SCE) are 0.40 V for C110 and 0.35 V for C360.
Both exceed the 0.25 V threshold commonly accepted for dry indoor environments. Under humid or salt-spray conditions per USCAR-2, the allowable potential difference tightens to 0.15 V, which neither alloy satisfies against aluminum without plating. Tin plating at a minimum of 2.5 µm with porosity below 5 pores per square millimetre is required for either alloy mating with aluminum in environments above 60% relative humidity.
Dezincification is the distinguishing corrosion risk. C360 (nominal composition Cu 63-65%, Zn 31-33%, Pb 2.5-3.7%) dezincifies in acidic environments below pH 5 or chloride atmospheres above 50 ppm.
Selective leaching of zinc from the alpha-brass matrix leaves a porous copper sponge structure that loses 40-60% of original tensile strength within 6 months of continuous exposure in severe environments. C110 (99.9% Cu minimum) is immune to dezincification. This makes C110 the required choice for terminals in industrial or marine environments with acid rain, chloride, or ammonia exposure risk.
Salt spray per ASTM B117: C110 unplated passes 24 hours before visible pitting (rapid Cu2O oxide formation to 20-30 nm). C360 unplated shows visible dezincification pitting within 96 hours. Tin plating extends C360 salt spray resistance to 120 hours but does not eliminate dezincification risk at coating holidays. A nickel strike barrier layer of 0.5-1.0 µm beneath the tin plating is required for C360 to prevent zinc diffusion through coating holidays, which occurs at approximately 1-2% of the holiday area within 500 hours of salt fog exposure.
[Data Anchor]: C110 copper is immune to dezincification. C360 brass loses 40-60% of tensile strength within 6 months in acidic environments below pH 5 due to selective zinc leaching. In chloride atmospheres above 50 ppm, C360 requires tin plating at a minimum of 2.5 µm plus a 0.5-1.0 µm nickel strike barrier layer to prevent zinc diffusion through coating holidays. Both alloys require tin plating for aluminum interface compatibility: C110 needs 2.5 µm minimum; C360 needs 2.5 µm tin + 0.5-1.0 µm nickel strike.
Processing Behaviors & Morphology
The processing profiles of C110 and C360 diverge across every parameter that matters to progressive die design. C110 stamps easily with wide clearance windows and minimal tool wear. C360 demands tighter process control and shorter tooling intervals but rewards with superior secondary machinability. The decision often hinges on whether the terminal is a net-shape stamping (C110) or a near-net-shape stamp-plus-machine part (C360).
Machinability vs Formability – Core Trade-off
Formability comparison: C110 at work-hardening exponent n = 0.35 accommodates a minimum bend radius of 0.5t and a blanking clearance window of 5-8% of material thickness. C360 at n = 0.15 requires a minimum bend radius of 1.5t and a tighter blanking clearance of 3-5%. C110 is significantly easier to stamp with wider process windows, lower tool wear, and higher press speeds (400 spm versus 250 spm maximum for C360 on a 60-ton press). Tooling resharpening intervals for C110 reach 500,000 strokes with carbide tooling versus 200,000 strokes for C360.
When secondary operations are required post-stamp — drilling cross-holes, threading, broaching — C360 is the practical choice among these two alloys. C110 produces long, continuous chips that tangle in automated machining cells, causing 15-25% downtime for chip clearing. C360 produces short, broken chips that clear via coolant flow. This 5x machinability advantage translates to a 60-70% reduction in secondary machining cycle time for C360 versus C110.
| Processing Parameter | C11000 (Annealed) | C36000 (Half-Hard) |
|---|---|---|
| Machinability Rating | 20 | 100 |
| Work-Hardening Exponent (n) | 0.35 | 0.15 |
| Minimum Bend Radius | 0.5 t | 1.5 t |
| Blanking Clearance (% thickness) | 5-8% | 3-5% |
| Chip Type (machining) | Long, continuous | Short, broken |
| Max Press Speed | 400 spm | 250 spm |
| Tooling Interval | 500,000 strokes | 200,000 strokes |
| Secondary Machining Cycle Time | Baseline (100%) | 30-40% of C110 |
[Data Anchor]: C110 copper at n = 0.35 accommodates 0.5t minimum bend radius and 5-8% blanking clearance, running at 400 spm with 500,000-stroke tooling intervals. C360 brass at n = 0.15 requires 1.5t minimum bend radius and 3-5% clearance, running at 250 spm with 200,000-stroke intervals. However, C110 produces continuous chips during secondary machining that cause 15-25% machine downtime. C360’s chip-breaking property eliminates this downtime, yielding a 60-70% reduction in secondary machining cycle time versus C110.
Springback & Dimensional Control
Springback behavior: C110 at 2-4 degrees for a 90° bend target. C360 at 4-7 degrees. The wider C360 springback range comes from lead particle distribution variability within the ASTM B16 composition tolerance of plus or minus 0.7% Pb. Batch-to-batch lead content variation shifts springback by approximately 1 degree per 0.5% Pb difference. Over the full composition window of 2.5-3.7% Pb, this creates a potential 2.4-degree springback variation between incoming coils.
Dimensional stability: both alloys hold plus or minus 0.05 mm on critical bend dimensions at 0.25 mm material thickness. However, C360 produces more consistent dimensional results within the same coil due to finer grain structure (ASTM grain size 7 at 32 µm versus C110 at ASTM grain size 6 at 45 µm). The trade-off is that C360 requires incoming coil hardness verification per ASTM E384 on every coil (not every heat) due to the 15-20 HV variation range typical of free-cutting brass. C110 accepts batch-level verification due to tighter incoming temper control.
[Data Anchor]: C360 brass springback varies by approximately 1 degree per 0.5% lead content variation within the ASTM B16 composition range of 2.5-3.7% Pb. This 1.2% Pb tolerance window creates a potential 2.4-degree springback variation between incoming coils. C110 springback is more consistent at 2-4 degrees with variation below 0.5 degrees between coils. C360 requires per-coil hardness verification per ASTM E384; C110 accepts batch-level verification.
Manufacturability & Industrial Applications
The C110-versus-C360 decision reduces to a single question: does the terminal carry current above 5 A? If yes, C110 is mandatory. If no, the decision depends on terminal geometry complexity, secondary machining requirements, and environmental exposure class. Kravzik maintains C110 strip inventory in thicknesses 0.15-1.5 mm and C360 strip in thicknesses 0.25-1.5 mm for stamped terminal production.
When to Specify C360 – Application Domains
C360 brass application domains include: (1) fuse clips and holders where current is below 5 A and the primary function is spring retention of the fuse element rather than continuous current conduction; (2) terminal blocks for industrial control panels where post-stamp threading of M2.5-to-M4 screw holes is required and secondary machining is the dominant process cost; (3) non-current-carrying structural brackets and alignment features within connectors; (4) ground terminals in dry indoor environments where conductivity is secondary to pull-out force retention.
All C360 applications require tin plating for corrosion protection unless the terminal operates in a climate-controlled indoor environment below 60% relative humidity. Plating thickness minimum of 2.5 µm with a nickel strike layer of 0.5-1.0 µm is required to prevent zinc diffusion through coating holidays. C360 terminal production is limited to 250 spm maximum with 200,000-stroke tooling intervals, which raises per-part cost approximately 15-25% versus C110 at equivalent stamping complexity.
[Data Anchor]: C360 brass is suitable for stamped terminal applications where current does not exceed 5 A and the primary function is mechanical retention, structural alignment, or post-stamp secondary machining. All C360 terminals require tin plating at a minimum of 2.5 µm plus a 0.5-1.0 µm nickel strike layer for operation in environments above 60% RH. Maximum press speed is 250 spm with 200,000-stroke tooling intervals, yielding a per-part cost 15-25% above C110 at equivalent stamping complexity.
When to Specify C110 – Application Domains
C110 copper application domains include: (1) all current-carrying terminals above 5 A; (2) power distribution terminals, battery connectors, and bus bar interfaces where 101% IACS conductivity is required to minimize I-squared-R losses; (3) terminals requiring net-shape stamping with tight bend radii below 1.5t; (4) RoHS/ELV-compliant automotive applications with zero regulatory exemptions required; (5) terminals in marine or industrial environments with chloride, acid, or ammonia exposure risk where dezincification immunity is mandatory.
C110 runs at 400 spm maximum on a 60-ton press with carbide tooling and 500,000-stroke resharpening intervals. Per-part cost for C110 stamping is typically 30-50% lower than C360 for net-shape parts at equivalent production volume.
When a design requires threaded features, Kravzik evaluates conversion to a pressed-in threaded insert or spring clip on a C110 substrate, eliminating both the secondary machining requirement and the lead-compliance and dezincification risks of C360. This press-fit fastener approach on C110 avoids the 60-70% machining cost premium of C360 while maintaining universal material compliance.
C110 limitations: cannot be used for terminals requiring secondary threading or cross-hole drilling in the base material (chip control issue). Must be tin plated at 2.5 µm minimum for aluminum interface compatibility. Limited to fewer than 1,000 mating cycles at room temperature for spring-beam applications (see the progressive die tooling guide for spring-force design limits).
[Data Anchor]: C110 copper runs at 400 spm with 500,000-stroke tooling intervals, 60% faster than C360 at 250 spm with 200,000-stroke intervals. Per-part cost for C110 net-shape stamping is 30-50% lower than C360. However, C110 is limited to fewer than 1,000 mating cycles at room temperature for contact beam applications and cannot support secondary threaded features without conversion to pressed-in inserts.
Data to Spec
You specified C360 brass for a fuse clip six months ago because the 5x machinability advantage over C110 made the post-stamp tapping step straightforward and the chip-breaking property kept the machining cell running without constant operator intervention. Six months into production, field failures show intermittent contact in terminals installed in outdoor telecom cabinets where the enclosure temperature reaches 65°C and humidity stays above 70% RH.
Root cause: dezincification at micro-cracks near the tapped thread, reducing clamping force by 40%. C110 was not considered because the drawing called for threaded features — but C110 could have been stamped with a press-fit threaded insert instead of machined threads, eliminating both the dezincification risk and the lead-compliance concern.
Kravzik reviews the terminal drawing for post-stamp operations and identifies whether the design can be converted to net-shape C110 stamping with pressed-in threaded inserts or spring clips, eliminating the secondary machining requirement and the dezincification risk. This press-fit fastener approach on C110 avoids both the lead-compliance issue and the 60-70% machining cost premium of C360. When C360 is the fallback option — existing tooling already cut, customer-specified alloy — we apply the nickel strike plus tin plating barrier verified by cross-hatch adhesion testing per ASTM D3359 and validate the terminal for its target operating environment. An internal inventory of both C110 and C360 strip in common thicknesses means prototype tooling trials can begin within 2 weeks of material and design verification.
Still specifying C360 by default and accepting the dezincification risk because the drawing calls for threaded features? Send us your terminal specs for a conversion assessment. Kravzik returns an alloy recommendation with press-fit insert feasibility evaluation, per-part cost comparison between C110 net-shape and C360 stamp-plus-machine, and plating compatibility validation within 48 hours.
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