Steel rail beveling according to your drawings

Steel rail beveling is a precision machining process used to create angled edges (bevels) on the ends or sides of railway rails, typically to prepare them for welding during track installation, repair, or manufacturing of turnouts, crossings, and expansion joints. The bevel geometry must strictly conform to the approved technical drawings, as even minor deviations can lead to weld imperfections, reduced joint strength, and premature track failure under heavy axle loads.

Standard rail profiles (e.g., UIC 60, AREMA 136RE, BS113A, ASCE, etc.) usually require double-V (X-type), single-V (K-type), or J-type bevels depending on the welding method: flash-butt welding, enclosed arc (aluminothermic) welding, or gas pressure welding. The most common is the double-V bevel for thermite welding of 60 kg/m and heavier rails.

Typical Bevel Dimensions (example for UIC 60 rail, thermite welding, EN 14811 / AREMA compliant)

· Rail height: 172 mm

· Bevel angle: 30° ± 2° from vertical (60° included angle)

· Root face (land): 1.5–2.5 mm

· Root gap when rails are butted: 16–20 mm (for preheating and portion placement)

· Bevel length along rail top: usually 60–80 mm

· Vertical misalignment tolerance: ? 0.5 mm

· Horizontal (lateral) alignment tolerance: ? 0.3 mm

These values are always superseded by the specific project or railway authority drawings. Some networks (e.g., Indian Railways RDSO, Chinese TB/T, Russian GOST) specify slightly different angles (28°–35°) and root faces.

Process Steps (field or depot)

1. Rail end cleaning: Remove rust, scale, grease, and old weld deposits using grinding or needle scaling.

2. Marking: Transfer exact bevel profile from the approved template or CNC program onto the rail end.

3. Cutting & rough beveling: – Oxy-fuel or plasma cutting for initial separation – Rail profile saw (abrasive disc) for straighter cuts

4. Precision beveling: – Dedicated rail beveling machines (e.g., Esab Railtrac, Geismar MP12, Robel 13.48, Cembre, or hydraulic milling units) – Milling cutters with indexable carbide inserts produce mirror-finish bevels in one or two passes – Some older systems still use manual oxy-acetylene beveling torches with multi-flame heads and rail-guided carriages

5. Final grinding: Remove cutter marks, ensure root face is flat and parallel, achieve surface roughness Ra ? 12.5 ?m.

6. Dimensional inspection: Use dedicated bevel gauges, templates, or 3D laser scanners to verify compliance with drawing tolerances.

7. Magnetic particle or ultrasonic testing of the prepared ends (especially for flash-butt welding plants).

Critical Requirements from Drawings

· All dimensions and tolerances must be read from the latest revision of the welding procedure specification (WPS) drawing.

· Special bevels for asymmetric profiles, insulated joints, or glued joints may have different angles (e.g., 1:4 or 1:6 slopes).

· High-strength rails (R350HT, R400HT) often demand narrower root gaps and tighter tolerances to prevent heat-affected zone cracking.

Accurate beveling directly influences weld quality, fatigue life, and ultrasonic inspectability of the finished joint. Deviations outside drawing tolerances are the primary cause of thermite weld rejections worldwide. Modern automated milling machines with digital template matching now achieve repeatability within 0.1 mm, dramatically improving joint reliability compared to manual methods.

In summary, steel rail beveling is a highly controlled operation where the approved technical drawing is the absolute authority; every angle, root face, gap, and alignment must be executed exactly as specified to guarantee safe, long-life rail welds under extreme cyclic loading.