Coimbatore is a manufacturing city that rarely gets the national attention it deserves. The city produces textile machinery components, wet grinders, pump sets, and motor windings that are exported globally. Its pump manufacturing cluster alone supplies markets across South and Southeast Asia. The engineering precision that goes into a Coimbatore-made pump or motor extends to every fastener in it which is why buyers in this market are specific about what they order.
At Stainless Bolt Industries, we manufacture and supply premium quality of SS hex bolts, nuts, and screws in SS 304 and SS 316 to maintenance contractors, and trading houses across Coimbatore, Tiruppur, Sulur, and the wider Kongu region. Bulk and regular supply, full documentation, and consistent grade material are what we bring to this market.
SS Hex Bolts in Coimbatore
Pump casing bolting, textile machinery frame assembly, motor housing connections, and structural bolting across Coimbatore’s industrial estates these drive hex bolt demand across both grades. SS 316 for any pump handling corrosive or chemical fluids; SS 304 for general mechanical assembly and structural work. We stock M6 to M100.
Available Types:
- Fully threaded hex bolts
- Partially threaded hex bolts (hex cap screws)
- Heavy hex bolts for structural applications
Sizes and Standards:
Sizes: M6 to M100 (metric) | 1/4″ to 4″ (inch)
Standards: ASTM A193, DIN 933, DIN 931, ISO 4014, ISO 4017
SS Hex Nuts in Coimbatore
Available Types:
- Standard hex nuts (DIN 934 / ISO 4032)
- Heavy hex nuts (ASTM A194)
- Coupling nuts
- Nylon insert lock nuts (SS hex nyloc)
- Flange nuts
Size Range and Standards:
Sizes: M4 to M100 | 1/4″ to 4″
Standards: ASTM A194 2H & 8M, DIN 934, ISO 4032
SS Screws in Coimbatore
Motor enclosure assembly across Coimbatore’s motor manufacturing cluster uses SS 304 machine screws and self-tapping screws in large quantities. Textile machinery producers use socket cap screws for frame and mechanism assembly. Tiruppur’s dyeing and processing units specify SS 316 machine screws for equipment in chemical bath contact zones.
Available Types:
- Self-tapping screws (pan head, countersunk, hex washer head)
- Machine screws (pan, CSK, round head Phillips and slotted)
- Hex head self-drilling screws (tek screws)
- Socket cap screws (Allen screws)
- Set screws (grub screws)
Size Range and Standards:
Sizes: M3 to M20 | #6 to 3/4″ (inch)
Standards: DIN 7981, DIN 965, DIN 912, ISO 1481
SS 304 vs SS 316 Fasteners
| Feature | SS 304 Fasteners | SS 316 Fasteners |
| Composition | 18% Chromium, 8% Nickel | 16% Cr, 10% Ni, 2% Molybdenum |
| Fluid Resistance | Good for water and general fluids | Essential for chemical and dye fluid pumps |
| Cost | Lower | Approx. 20–30% higher than 304 |
| Best for Coimbatore | General pumps, motors, textile machinery, structural | Chemical pumps, dyeing units, process equipment |
Applications across Coimbatore's Sectors:
Pump Manufacturing: Coimbatore’s pump manufacturers supply domestic water pumps, chemical process pumps, agricultural pumps, and industrial fluid handling equipment. Chemical service variants use SS 316 for casing bolts, flange connections, and impeller shaft fasteners. Water service pumps use SS 304 for most bolted connections. Both need dimensional accuracy and consistent grade.
Textile Machinery Manufacturing: Coimbatore produces warping, weaving, and sizing machinery that goes to mills across India and abroad. Frame assembly, mechanical drive components, and enclosure fasteners use SS 304 hex bolts and machine screws. The export destination of the machinery often determines documentation requirements some export orders require EN 10204 3.1.
Motor and Electrical Equipment Manufacturing: Electric motor manufacturers in Coimbatore supplying pump motors, industrial motors, and agricultural pump sets use SS 304 machine screws and self-tapping screws for enclosure assembly and terminal connections. Consistent grade and dimensional accuracy are the requirements.
Dyeing and Processing: Tiruppur’s garment and knitwear dyeing industry uses large quantities of SS 316 machine screws and hex bolts for dyeing machine assembly and plumbing connections. Dye chemicals and bleaching agents are corrosive to SS 304; 316’s chemical resistance makes it the only sensible specification here.
General Industrial: Coimbatore’s general industrial estates house engineering fabricators, equipment manufacturers, and maintenance contractors. SS 304 hex bolts and nuts in M8 to M24 are high-velocity items in this segment, covering everything from machine frames to structural connections.
Why Coimbatore Buyers Choose Stainless Bolt Industries:
- EN 10204 3.1 MTCs for pump and machinery export documentation
- Stock depth on M8 to M20 SS 304 and SS 316 for high-volume pump sector orders
- Bulk supply capability for pump manufacturer production schedules
- Custom lengths for specific pump casing and machinery assembly requirements
- GST-compliant invoicing for Tamil Nadu buyers with Pan-India dispatch
Technical Specifications
| Product | Grade 304 Standard | Grade 316 Standard |
|---|---|---|
| Hex Bolts | ASTM A193 B8 | ASTM A193 B8M |
| Hex Nuts | ASTM A194 Grade 8 | ASTM A194 Grade 8M |
| Screws | AISI 304 / DIN | AISI 316 / DIN |
Frequently Asked Questions
SS 316 for any pump handling chemicals, acids, dyes, or effluents. The chloride and chemical resistance of 316’s molybdenum content is what separates a 2-year service life from a 15-year one in corrosive fluid handling. For water service pumps, SS 304 is sufficient.
Yes. SS 316 hex bolts, machine screws, and hex nuts are stocked for Tiruppur’s dyeing sector. Dye chemicals are corrosive enough that 304 is not a defensible specification for equipment in regular chemical contact.
Yes. EN 10204 3.1 Mill Test Certificates are standard with every order. Export-bound machinery from Coimbatore sometimes requires specific documentation dimensional inspection reports are available on request.