Brass Flat Bar for Bearing Plates, Wear Strips and Machine Parts
Brass Flat Bar Suppliers – Bronzeoilless.com
A brass flat bar is rectangular copper-zinc stock supplied in straight lengths, cut to size and then machined into the parts that carry sliding or compressive load: bearing plates, wear strips, guide liners, valve bodies, gear blanks and terminal stock.
Discover superior stability and durability with our brass flat bar bearing plates. Engineered for precision performance, these plates offer corrosion resistance and seamless integration for reliable operation in diverse applications.
What brass flat bar is
Brass is a copper-zinc alloy. Zinc content typically sits between 30% and 40%; below about 35% zinc the alloy stays single-phase and works well cold, above it a second phase appears that raises strength and hardness but reduces cold formability. Small additions change the behaviour in ways that matter in service:
- Lead (roughly 2–3.5%) is added for machinability. It sits as discrete particles that break the chip, which is why free-cutting brass produces short chips and holds tight dimensional work at high feed rates. It also lowers strength slightly and rules the alloy out of potable-water and lead-free specifications.
- Tin (around 1%) improves resistance to seawater corrosion. Naval brass is the common name for this family.
- Aluminium and manganese raise strength and hardness. At the higher end of the range the alloy is better described as a high-strength brass and is used for slide blocks and graphite-plugged wear plates.
- Arsenic, antimony or phosphorus in small amounts inhibit dezincification in grades intended for water service.
Flat bar is produced by extrusion or by rolling and then straightening, and is supplied in the as-extruded or as-rolled condition unless a temper is specified. From there it is sawn, milled, drilled and tapped. Because the section is rectangular, it suits parts that would be wasteful to make from round bar — a bearing plate 20 mm thick by 60 mm wide has most of its material where it is needed.
Grades and typical properties
The values below are typical for the forms we supply at room temperature. Actual figures depend on section thickness, temper and the standard referenced, so the material certificate issued with the order governs.
| Designation | Nominal composition | Tensile strength | Hardness | Character | Where it goes |
|---|---|---|---|---|---|
| CuZn39Pb3 (CW614N, CZ121, C38500) | Cu 57.5–59.5%, Pb 2.5–3.5%, Zn remainder | 360–450 MPa (52,000–65,000 psi) | 90–120 HB | Free-cutting, the reference against which machinability ratings are set; not for potable water | Bearing plates, valve bodies, gear blanks, turned and milled parts |
| CuZn37 (CW508L, CZ108, C27200) | Cu 62–64%, Zn remainder | 340–440 MPa (49,000–64,000 psi) | 80–110 HB | Cold-formable, bends and spins well; machinability lower than the leaded grades | Formed brackets, bent wear strips, shims, terminal and connector stock |
| CuZn38Sn1 (CW719R, CZ112, C46400 naval brass) | Cu 59–62%, Sn 0.7–1.1%, Zn remainder | 380–480 MPa (55,000–70,000 psi) | 90–130 HB | Tin addition for seawater and brackish water service | Marine hardware, pump and valve trim, shaft liners, deck fittings |
| CuZn40Al2 (CW / 2.0550) | Cu 56–60%, Al 1.4–2.2%, Mn and Zn remainder | 500–620 MPa (72,000–90,000 psi) | 130–170 HB | Higher strength with usable sliding behaviour; machines acceptably | Slide blocks, gib strips, lifting equipment wear pads |
| CuZn25Al6Mn4 (high-strength manganese brass) | Cu 62–66%, Al 5–7%, Mn 3–5%, Zn remainder | 600–750 MPa (87,000–109,000 psi) | 180–230 HB | Used with embedded graphite plugs where the joint runs dry | Graphite-plugged wear plates, heavy slideways, high-load pivot liners |
Grade names cross between EN, BS and UNS systems with some spread in composition limits. Where a drawing states only one designation, we confirm the standard revision before quoting. A general comparison of copper alloy families is on the common bearing materials page.
Brass Flat Bar – Sizes and tolerances
Stock is held in a range of thickness and width combinations, and lengths are cut to order. Tolerances below are typical for as-supplied stock; tighter figures are achievable by machining the faces after cutting, which is what we do for bearing plates and slideway liners.
| Dimension | Typical stock range | Typical tolerance as supplied | Note |
|---|---|---|---|
| Thickness | 3–50 mm (0.12–2.0 in) | ±0.10–0.30 mm (0.004–0.012 in), widening with section | Milled faces bring this to ±0.05 mm where the part needs it |
| Width | 10–200 mm (0.39–7.9 in) | ±0.20–0.50 mm (0.008–0.020 in) | Wider sections above 200 mm are supplied as plate rather than bar |
| Length, cut to order | 300–3,000 mm (12–118 in) | ±1–3 mm (0.04–0.12 in) on saw cut | Machined ends hold ±0.2 mm; longer lengths by arrangement |
| Flatness | — | ≤0.5 mm over 300 mm as supplied; ≤0.1 mm over 300 mm after machining | Flatness matters more than thickness on a bearing plate — an unflat plate loads one edge |
| Surface finish | — | Ra 1.6–3.2 µm (63–125 µin) as extruded or rolled; Ra 0.8 µm (32 µin) or better machined | Specify the mating face finish separately from the cosmetic faces |
| Holes, slots, countersinks | Per drawing | Hole position ±0.2 mm typical; diameter to H9 or per drawing | Countersunk fixings should sit below the sliding face |
Long Lasting Bronze Flat Bar
Rely on the enduring durability of our bronze flat bar bearing plates, fortified with superior corrosion resistance. Engineered to withstand harsh environmental conditions and chemical exposure, these plates maintain their integrity and performance even in the most demanding environments. Whether you’re operating in marine or industrial settings, our bearing plates provide steadfast protection against rust and degradation, ensuring long-term reliability and peace of mind.
Where brass flat bar goes in a machine
The uses that matter in our work are mechanical. Brass flat bar is stock for parts that slide, carry compressive load, seal against a fluid or conduct current — not for decorative trim, although the same section is occasionally used for architectural hardware.
| Use | Grade usually specified | Reason |
|---|---|---|
| Bearing plate and saddle liner | CuZn39Pb3 or CuZn40Al2 | Flat, machinable, carries compressive load with grease or oil present |
| Wear strip on a slideway or guide | CuZn37 or CuZn40Al2 | Formable to the run of the way; fixed with screws or bonded, replaced without dismantling the machine |
| Gib and guide liner | CuZn40Al2 | Higher strength resists the edge load a gib takes; see the oil-free L-gibs form |
| Valve body, seat and trim parts | CuZn39Pb3 or CuZn38Sn1 | Free-cutting for complex passages; the tin grade where water contact is continuous |
| Gear and worm wheel blanks | CuZn39Pb3 | Machines to a clean tooth form and runs against a steel worm |
| Electrical connectors and terminal stock | CuZn37 or CuZn39Pb3 | Conductivity around 25–28% IACS with better strength and spring behaviour than pure copper |
| Marine hardware and fasteners | CuZn38Sn1 | Tin addition for seawater; standard brass dezincifies in that service |
| Plumbing and pipe-work components | CuZn39Pb3, or a dezincification-resistant grade for potable water | Threads cleanly and seals well against tapered threads |
Two of those uses deserve a note. Bearing plates and wear strips are the reason most of this material is bought from us: a brass plate under a sliding saddle or a machine slideway is cheap to replace, can be re-machined in place, and will not gall against a steel counterface the way a steel-on-steel pair can. The wear plate and liner range covers the same duty where load rises beyond what brass carries, and the machine tool wear plates page covers the slideway case in more detail.
Electrical and plumbing uses share the material but not the design constraints: conductivity and thread strength, rather than load and wear. Valve trim is the meeting point, and the valve bushing and brass slip ring pages show those forms.
Machining and fitting notes
- Cutting. Free-cutting grades run at high feed with carbide or high-speed steel tooling and break chips cleanly. Use positive rake and keep the tool sharp; a dull tool smears rather than cuts.
- Drilling. Peck deep holes to clear chips. Leaded brass drills freely but work-hardens if the tool rubs.
- Joining. Soldering and silver brazing work with the correct flux. Fusion welding is not recommended on leaded grades — lead has a low melting point and the alloy is hot-short; mechanical fixing or brazing is the usual route.
- Forming. CuZn37 bends well; the higher-zinc and leaded grades crack if bent across a tight radius. Stress-relieve after heavy forming.
- Fitting a bearing plate. Machine the mounting face flat, fix with countersunk screws that sit below the sliding surface, and leave room for thermal growth — brass expands more than the steel frame it is bolted to, roughly 20 × 10⁻⁶ per K against about 12 × 10⁻⁶ per K for steel. On a 500 mm (19.7 in) plate a 40 K rise gives about 0.16 mm (0.006 in) of growth.
- Lubrication. Cut grease grooves into the sliding face where the duty allows it. Without a groove, grease is pushed out of the contact within a few strokes.
- Inspection. Check thickness and flatness on the same reference faces used for machining, at 20 °C (68 °F).
When brass flat bar is the wrong choice
Brass is a general-purpose material, not a bearing material for every duty. Specify something else when:
- Load and shock are high. Brass flat bar suits moderate compressive load with grease. Once the contact pressure or the impact rises, move to a bronze — see bronze wear plate or the CuZn40Al2 slide blocks used on lifting equipment.
- The joint runs dry. Plain brass has no embedded lubricant. A graphite-plugged bronze wear plate handles dry sliding at meaningful PV; see the graphite-filled bronze option.
- The service water is warm, soft or chlorinated. Standard brass dezincifies, leaving a porous copper layer. Use a dezincification-resistant brass, naval brass or a bronze.
- Ammonia, amines or mercury are present. Brass is prone to stress-corrosion cracking in those environments, particularly in cold-worked or unrelieved parts.
- Temperature is sustained above roughly 150–200 °C (300–390 °F). Strength falls away and the lead-bearing grades are limited well below that. Bronze covers the higher range.
- Lead-free is required. CuZn39Pb3 does not meet RoHS or potable-water lead limits. Specify a silicon brass, a low-lead brass or a bronze and say so on the drawing.
- The part is structural. If it carries tensile load in the frame, steel is the correct call and brass is not a substitute.
What to send for a quotation. Section (thickness × width), length or cut lengths, grade or the standard referenced, quantity, and whether faces need machining, holes, slots or countersinks. For bearing duties, add the load, speed, temperature and what the plate slides against.
Flat Wear Plate self-lubricating
Self-lubricating wear plates, such as those made from aluminum bronze with oil-impregnated graphite plugs, are designed for various industries like steel mills, pipelines, and mining. These plates provide a durable wear surface for molds requiring slides, cams, or flat surfaces, with features like low friction coefficients and tight tolerances for easy installation.
They are used to guide and control linear motion in applications where gravity is a factor and are particularly beneficial in heavy-duty applications due to their maintenance-free bearing material and excellent performance under high loads.
These wear plates come in standard inch and metric sizes, with options for custom configurations based on specific needs like size, hole patterns, or graphite patterns.
Additionally, self-lubricating wear plates are available in various materials like steel or aluminum bronze, providing a long-lasting solution for molds requiring specific surface characteristics.
Frequently Asked Questions (FAQs)
Durable Oil-Free Wear Plates for Heavy-Duty Applications
Email us your production files, or reach out to schedule a call with our expert team.
Email us your production files, or reach out to schedule a call with our expert team.
Email us your production files, or reach out to schedule a call with our expert team.
Email us your production files, or reach out to schedule a call with our expert team.
Email us your production files, or reach out to schedule a call with our expert team.
Email us your production files, or reach out to schedule a call with our expert team.
