§1What this business is
Cast-iron ring blanks are bought from local foundries, cleaned and ground, then faced, turned and bored to size; a gap is cut so the ring springs against the cylinder wall. Rings are then given a surface treatment such as chrome, phosphate or tin coating. They are a regular replacement part in vehicle and machine engines.
Capacity: 150 rings a day, 45,000 a year; year 1 at 65%. Castings: 15,600 kg a year at ₹60 a kg.
§2Is it right for you?
Who it is for
A machinist or auto-parts trader with access to foundries and spare-parts dealers.
Who it is not for
Someone without precision-machining experience.
Advantages
- Piston rings are a regular replacement part
- Used in vehicles, compressors, pumps and railway engines
- Castings are bought ready from local foundries
- High margin in the report
Drawbacks
- Precision work — out-of-tolerance rings are rejected
- Big ring brands hold the vehicle-maker market
- Coating or plating must be arranged
- Lathes are a large share of the cost
Skills you need
- Precision turning and grinding
- Gauging and inspection to IS 5791 and IS 8422
- Buying good cast-iron blanks
- Selling to spare-parts dealers
Why difficulty 3/5: Precision machining and quality control against established brands.
§3Market
Who buys
- Automobile spare-parts dealers
- Engine and compressor repair workshops
- Pump and compressor makers
How it sells
- Spare-parts wholesalers
- Direct supply to workshops and manufacturers
Good to know
- The report lists uses in railway engines, compressors, steam hammers, cars, pumps, cranes and gearboxes.
§4Raw material & machinery
| Item | Qty | Cost |
|---|---|---|
| Lathe, 1,800 mm bed, 3 HP motor | 1 | ₹4,50,000 |
| Lathe, 900 mm bed, 2 HP motor | 1 | ₹3,50,000 |
| Face grinder with special attachment, 4 HP | 1 | ₹85,000 |
| Bench drill, 12 mm | 1 | ₹25,000 |
| Bench grinder, 250 mm wheel, 1 HP | 1 | ₹25,000 |
| Gauges, tools and other equipment | 1 lot | ₹60,000 |
| Installation and electrification | — | ₹1,00,000 |
From: PMEGP sample project report — Piston Ring (prepared by Udyami/Samadhan)
- Cast-iron piston-ring castings (blanks)15,600 kg a year at ₹60 a kg; bought from local foundries
- Coating materials (chrome, phosphate, tin, molybdenum etc.)surface treatments listed in the report
From: PMEGP sample project report — Piston Ring (prepared by Udyami/Samadhan)
§5Licences & registration
- Udyam
- GST
- NOC from the State Pollution Control Board (report)
- Standards: IS 5791 and IS 8422 for IC-engine rings (report)
§6Schemes & subsidies
PMEGP (report is a PMEGP sample); CGTMSE for collateral-free credit. The cost is above the ₹20 L MUDRA limit.
§7Money
How the investment is worked out: Samadhan report: shed ₹4.00 L, plant & machinery ₹10.95 L, furniture ₹1.00 L, pre-operative ₹0.66 L, working capital ₹5.39 L = ₹22.00 L. Land own or rented.
Working capital: ₹5.39 L, bank finance ₹4.85 L.
Year not printed on the report — check current machinery prices.
§8Export potential
Confirm the HS code in the DGFT ITC(HS) lookup before you export
Export council / board: EEPC India
- HS codes are from the WCO HS 2022 list; confirm the 8-digit ITC(HS) line with DGFT or your customs broker.
- You need an Import Export Code (IEC) from DGFT before the first shipment.
§9Risks — where people fail
- Quality rejections
- Competition from brands
- Fewer engines to service as vehicles go electric
- Dealer credit
§1030 / 60 / 90-day plan
A general plan that applies to any business. A plan for this business will be added after research.
- Days 1–30: Visit a working piston ring machining unit, ask 10 buyers about price and quantity, and get quotations from 3 suppliers.
- Days 31–60: Udyam and the licences you need (Udyam, GST), a project report (DPR), and the scheme or loan file.
- Days 61–90: Space and machines, trial production, and first deliveries to 10 customers.
§11Who to connect with
Associations, clusters and training institutes — the directory is being built. Connect
§12Watch
There is no episode on this business yet. Shows are coming soon on the Podcast page.
Want to start Piston Ring Machining?
DPR, loan file or registration — ask us on WhatsApp.
¶Sources
Data review: 6 October 2026. Spotted a mistake? Report it. For information only — not legal or financial advice.