IS 1030:2018 is the Indian Standard (BIS) for carbon steel castings for general engineering purposes. IS 1030 is the primary specification for carbon steel castings in India. Five grades based on tensile strength (410-620 MPa). All grades require heat treatment. Used for valve bodies, pump casings, crane components, and general engineering castings requiring ductility and weldability.
Specification for carbon steel castings for general engineering covering grades, chemical composition, mechanical properties, heat treatment, and NDT requirements.
Key reference values — verify against the current code edition / project specification.
| Reference | Value | Clause |
|---|---|---|
| Subject | Carbon steel castings, general engineering | Scope |
| Defined by | Grade — yield, UTS, elongation class | Grades |
| Chemistry | C/Mn/S/P limits per grade | Composition |
| Heat treatment | Annealed/normalised/tempered as specified | Process |
| NDT | Radiography/UT/MPI per criticality | QC |
| Use | Cast brackets, bearings, machinery & structural castings | Application |
IS 1030:2018 is the Indian Standard for Carbon Steel Castings for General Engineering Purposes — Specification. It covers sand-cast and similar process-cast carbon-steel components used in:
Use it when: - Procuring cast steel components to specification - Auditing foundry compliance — chemistry, mechanical properties, surface quality, non-destructive testing - Specifying replacement parts in maintenance — match original casting grade for fit-for-purpose - Investigating service failures of cast components — chemistry / mechanical / micro-structure verification
Does NOT cover: - Stainless steel castings → see IS 6603 (stainless bars), IS 11144 (austenitic stainless castings) - Cast iron (grey iron, malleable, ductile) → IS 210, IS 1862, IS 1865:2018 - Alloy steel castings → IS 4368 - Carbon steel forgings (different process) → IS 4367, IS 5517
Grade designation system (Clause 3): IS 1030 grades are named by specified minimum tensile strength in MPa, e.g.:
The number before the hyphen is yield (Re or 0.2% proof); after is UTS (Rm). Tested per IS 1608 Part 1:2005.
Chemistry envelopes (Table 1): - C: 0.18-0.40% (varies by grade; lower C = more weldable; higher C = higher strength) - Si: ≤ 0.60% (mostly residual) - Mn: 0.50-1.50% (alloying for strength) - P: ≤ 0.045% - S: ≤ 0.045%
Heat treatment conditions (Clause 5) — castings may be supplied in: - As-cast condition (lowest cost; coarser grain; lower toughness) - Normalized (austenitised + air-cooled; refined grain; better toughness; standard for most engineering use) - Normalized and tempered (further toughness improvement; standard for impact-loaded components) - Quenched and tempered (highest strength + toughness; for premium grades)
Mechanical property requirements (Table 2 of IS 1030:2018, condensed):
| Grade | Yield min (MPa) | UTS min (MPa) | Elongation min (%) | Charpy V impact (J, room temp) | |---|---|---|---|---| | 200-400 | 200 | 400 | 25 | 27 | | 230-450 | 230 | 450 | 22 | 25 | | 280-520 | 280 | 520 | 18 | 22 | | 340-570 | 340 | 570 | 15 | 20 | | 400-630 | 400 | 630 | 12 | 18 | | 540-720 | 540 | 720 | 8 | 14 |
Acceptance testing per heat (Clause 8): minimum one tensile + one impact + chemistry per heat-treatment batch. Mass production castings sample 1 in 10 to 1 in 50 castings depending on Grade and application criticality.
Surface quality (Clause 7) — three quality grades by NDT requirements:
Common application defects to look for: - Shrinkage cavities — internal voids from solidification shrinkage; detected by UT/RT - Hot tears — cracks from thermal stress during solidification; surface or sub-surface; MPI/DPT detection - Sand inclusions — sand from the mould trapped in casting; visual + UT - Slag inclusions — non-metallic impurities; chemical analysis + UT - Cold shuts — incomplete fusion; surface defects; visual - Porosity — gas bubbles; UT/RT
Repair welding (Clause 9): permitted for surface and minor sub-surface defects. Repaired castings must be retested by relevant NDT method. Major repair welds require full post-weld heat treatment.
Material identification: every casting must be stamped or cast-in with manufacturer's mark, grade, heat number, and IS 1030:2018 reference. This is critical for failure analysis traceability.
1. Wrong grade for application — using 200-400 (mildest) for impact-loaded structural component, or 540-720 (highest strength but lowest toughness) for low-temperature impact application. Match grade to actual service stress, temperature, fatigue cycles.
2. No NDT specification — Grade A (no NDT) is fine for non-critical components but inappropriate for pressure-containing, lifting, or safety-critical. Specify Grade B or C with appropriate NDT level on drawings.
3. As-cast supply where heat treatment required — as-cast carbon steel has coarse grain and unpredictable properties. Always specify normalized condition at minimum for engineering applications. Heat treatment cost is small relative to property assurance.
4. Inadequate impact test specification — for low-temperature service (cold storage, Himalayan applications, refrigeration), Charpy V impact tested at the service temperature is essential. Room-temperature impact alone is not enough.
5. No traceability — missing heat number, manufacturer's mark, or grade markings makes failure analysis impossible. Mandate complete stamping per Clause 11.
6. Repair welding without post-weld heat treatment — major weld repairs leave residual stresses. PWHT (normalising or stress-relief) is mandatory. Skipped PWHT can cause cracking from residual stress + service loads.
7. Pickling acid residue — castings cleaned with acid pickling can retain hydrogen and cause hydrogen embrittlement, especially in higher strength grades (Grade 400-630, 540-720). Mandate post-pickling baking treatment (175-200°C for 4+ hours).
8. Wrong machinability assumption — Grade 280-520 (typical workhorse grade) has fair machinability. Higher grades (540-720) have poor machinability and may need special tooling. Plan production / repair work accordingly.
9. Mixing IS 1030 with IS 1865 (cast iron) in repair / replacement** — they look similar but have very different properties. IS 1030 is steel (ductile, weldable); IS 1865 is ductile iron (limited ductility, harder to weld). Material substitution causes service failures.
IS 1030:2018 is the current revision (replacing IS 1030:1998), well-aligned with international practice. The 2018 revision added newer high-strength grades (Grade 400-630, 540-720) for advanced engineering applications and tightened NDT acceptance levels.
Indian foundry market: - Major suppliers (TAFE Castings, Aurangabad Group, Hosur Foundries, Mahalakshmi Smelters): BIS-licensed, IS 1030:2018 compliant, with full traceability and NDT. Premium pricing (₹70-130/kg). - Mid-tier foundries (regional, smaller): variable QC. Pre-qualify with sample test + factory audit before bulk procurement. Pricing ₹40-80/kg. - Small-batch artisan foundries: useful for one-off / restoration work. No formal certification. Quality verification on every batch.
Procurement pattern: most large industrial / pump / valve / railway component buyers maintain AVL (Approved Vendor List) with technical audit (per ISO 9001-derived foundry audit protocol). For one-off projects, sample-batch testing + manufacturer reputation + visual inspection of similar previous work is the practical assurance approach.
For replacement parts in existing equipment: identify the original material grade from the equipment manual or maker's drawing. If unknown, do material identification testing (chemistry + hardness) on the failed/worn part before specifying replacement.
Future: castings are facing competition from fabrication-and-welding (using IS 2062 structural-steel plates welded into the same geometry) for medium-complexity components. Fabrications are cheaper for short runs, castings cheaper for long runs. The cost crossover is around 50-100 pieces depending on geometry complexity. For high-volume mass-production (railway wagons, pump bodies), castings remain dominant.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Grade 1 tensile | Min 410 MPa | Min 414 MPa (60 ksi) | ASTM A27 Gr 60-30 |