Billets vs RCS — what's the difference?
A billet is a semi-finished square section, usually produced on a continuous casting machine (CCM) and used as feedstock for rolling mills and forging presses. An RCS (round corner square) is a hot-rolled square section with rounded corners — typically smaller, with a better surface and more consistent dimensions, used by re-rollers who want to start closer to their finished size.
1. Section size and length
Match the section to your mill's first stand or your press, and the length to your reheating furnace. At Navkardeep we supply:
| Product | Section | Length | Condition |
|---|---|---|---|
| Billets | 75×75 to 140×140 mm | Up to 9 m, or as required | As cast, spot ground or fully ground |
| RCS | 45×45 to 90×90 mm | 3 – 6 m | As rolled black or hot rolled annealed |
2. Chemistry — per heat, not per lot
Each heat is a separate melt with its own chemistry. Insist on a certificate that lists the heat number and the full analysis for that heat, and make sure the heat number is marked on the material. For 200-series grades, check manganese and nitrogen as well as chromium and nickel; for 316, confirm molybdenum.
3. Surface condition
As-cast surfaces can carry oscillation marks, laps or scale. Surface defects on a billet become seams and slivers on the finished bar. Decide what you need:
- As cast — lowest cost, suitable when your process tolerates or removes surface defects.
- Spot ground — visible defects ground out.
- Fully ground — entire surface ground; the choice for bright bar and critical forgings.
4. Internal soundness
Centre porosity, segregation or pipe inside a billet can open up during rolling or forging. Ask how internal quality is controlled — casting practice, macro-etch checks, or ultrasonic testing for critical orders.
5. Straightness, squareness and cut ends
Bent billets jam pushers and furnaces; rhomboidity (out-of-square) causes rolling defects. Specify limits if your line is sensitive, and ask for clean, square cut ends.
6. Traceability
The most reliable supply comes from a producer who melts and casts in-house: the heat number on your billet ties directly to a chemistry measured before casting. Navkardeep casts billets on our own 4/7 m radius CCM at Vijapur from heats verified on an optical emission spectrometer — see our infrastructure.
Ready to specify? Share section, grade, length, surface condition and quantity through our quote form.