50kg rail (P50)
Quenched & tempered U71Mn rail with ≥880 MPa tensile strength; durable, low life-cycle cost and ready for mainline, industrial and crane track applications.
Product Overview
Our 50kg rail (often referenced as P50 rail or 50 kg/m rail; theoretical weight 51.514 kg/m) is manufactured to GB/T 2585-2021 and CRCC certified.
Produced from U71Mn steel with precision quench and temper treatment, the rail delivers tensile strength ≥880 MPa and head hardness HBW 260–300. With vertical/side wear damage limits of 10 mm / 17 mm and fatigue life improved by over 25% versus ordinary rails, it reduces replacement frequency and operational downtime.
The classic 50kg rail profile (50kg rail height 152 mm) and standard 50kg rail dimensions (base width 132 mm, head width 70 mm, web 15.5 mm) fit existing fastenings and sleepers without modification. Standard lengths: 12.5 m and 25 m; bespoke 100 m long rails and weathering or anti-corrosion finishes available.
Batch traceability, 16-point QC and 72-hour dispatch for bulk orders make this an efficient, reliable supply solution.
Technical Specifications
Parameter | Value | Notes |
Model / Marking | 50 kg/m | Industry standard nominal weight (P50 type heavy rail) |
Material | U71Mn high-carbon steel | Excellent wear resistance, fatigue resistance and load-bearing capacity, suitable for heavy-duty scenarios |
Theoretical weight | 51.514 kg/m (~34.6 lb/ft) | Actual ±3% permitted (per GB/T standard for heavy rail) |
Standard lengths | 12.5 m / 25 m (custom up to 25 m) | Custom lengths available for special projects — please confirm at enquiry |
Execution standard | GB/T 2585-2017 (Hot-rolled Heavy Rail) | National authoritative standard for mainline and heavy-haul heavy rail products |
Mechanical properties | Yield ≥ 580 MPa; Tensile ≥ 880 MPa | Suitable for passenger and freight trains, heavy-duty mining and port transport |
Surface treatment | Natural rust / passivation / anti-corrosion coating options | Improves corrosion resistance in damp, dusty or coastal harsh environments |
Manufacturing & testing process
Rolling & dimensional control — continuous casting at ~1250 °C followed by precision rolling on universal mill; dimensional tolerance within ±0.5 mm to ensure uniform stress distribution across the 50kg rail profile.
Heat treatment — quench at 900–950 °C followed by tempering at 450–500 °C to relieve stresses and enhance toughness and wear resistance in the 50kg rail.
Quality inspections (16 checkpoints) — visual inspection, dimensional measurement (verifying 50kg rail dimensions and height), ultrasonic flaw detection, drop-weight impact testing, hardness checks, chemical & mechanical property verification. Non-conforming rails are rejected and recorded.
Typical applications
Conventional passenger & freight branch lines — suitable for National Grade III and below; axle load ≤25 t; operating speeds ≤120 km/h.
Industrial transport lines — robust against frequent start/stop and heavy loads in steelworks, coal mines and cement plants (20–50 t rolling stock).
Crane and special track — custom-modified profiles can be supplied to suit bridge cranes, gantry cranes and temporary repair works.
Key advantages
High strength & abrasion resistance, lower whole-life cost
The P50 rail (50kg rail) is made from U71Mn and heat-treated by quench + temper to achieve ≥880 MPa tensile strength and HBW 260–300 head hardness. Fatigue life is increased by 25%+, reducing replacement frequency and downtime in heavy-use environments.Plug-and-play compatibility — standard 50kg rail profile
Manufactured to GB/T 2585-2021 with the standard 50kg rail profile (50kg rail height 152 mm), this rail fits common sleepers and fastenings used on conventional passenger/freight lines, industrial tracks and crane rails — usually without modification.Complete traceability & strict quality control
From 1250 °C continuous casting to precision rolling and finishing, each rail passes 16 QC steps (visual & dimensional checks, ultrasonic testing, drop-weight impact, hardness testing) and receives a unique traceability code. CRCC inspection certificates are available per batch.Flexible supply & environment-specific options
Standard lengths: 12.5 m and 25 m; custom 100 m long-rail production available. Options for coastal/high-humidity environments include weathering steel (U75VNbRE) and anti-corrosion coatings; export packaging includes phosphating + epoxy for sea transport. Bulk orders of 50 kg/m rail can be shipped within 72 hours from nearest depot.
Procurement & after-sales
Pricing — flexible quotes (tax & freight options available). Volume discounts and long-term supply contracts supported.
Customization — weathering steel, corrosion coatings, long-rail manufacturing and tailored packaging for export. Custom design packages provided within 7 working days.
Logistics & export — local dispatch hubs, sea-grade anti-rust packaging, and customs/clearance support for export customers.
Support — installation guidance manual, 24/7 technical hotline, warranty with free replacement for verified manufacturing defects.
FAQs
Q:Is P50 rail the same as 50 kg/m rail?
A:Yes. P50 rail, 50kg rail and 50 kg/m rail are equivalent designations referring to the same 50 kg class rail profile and dimensions.
Q:Do you provide samples or small trial orders?
A:Yes. Samples or small trial lots can be arranged (sample logistics and costs depend on destination); contact our sales team to arrange.
Q: Do you provide test reports and certificates for the P50 rail?
A:Yes — each batch is supplied with CRCC inspection certificates, chemical & mechanical test reports, and a unique traceability code for every rail.