Bolts Manufacturer in Mumbai, India

Premier Industrial Bolts Manufacturer & Global Exporter in Mumbai, India

Neelkamal Alloys LLP is a globally recognized B2B manufacturer, stockist, and exporter of high-precision industrial bolts, high-tensile fasteners, and corrosion-resistant alloy bolting solutions based in Mumbai, India. Operating under strict ISO quality management systems, we produce high-grade hex bolts, heavy hex structural bolts, flange bolts, stud bolts, U-bolts, anchor bolts, and custom drawing-based fasteners engineered specifically for critical engineering applications.

Our manufacturing plant combines state-of-the-art multi-station cold forging machines, heavy-duty hot forging presses, and precision CNC turning centers. This allows us to deliver high-yield bolts from standard metric sizes (M2 to M160) to imperial threads (1/4" to 6" diameter) with lengths up to 2000mm. Serving EPC contractors, process equipment fabricators, offshore engineers, and industrial distributors in over 105 countries, Neelkamal Alloys LLP guarantees 100% material traceability, heat-number verification, and full compliance with international standards including ASME, ASTM, DIN, ISO, and BS.

Featured Industrial Bolt Categories

Stainless Steel Hex Bolts — Hex Head Bolts

Socket Head Allen Bolts — Allen & Socket Cap Bolts

Forged Eye Bolts — Forged Lifting Eye Bolts

Comprehensive Engineering Specifications & Standards

To ensure flawless performance under elevated temperatures, high pressures, and aggressive corrosive environments, our bolts are tested and manufactured according to exact international dimensional standards and material specifications.

Specification Parameter	Manufacturing Details & Options
Dimensional Standards	ASME B18.2.1, ASME B18.2.3.5M, ASME B18.5, DIN 931, DIN 933, DIN 6914, ISO 4014, ISO 4017, ISO 8765, IS 1363, IS 1364, BS 1083, BS 1768
Size Range	Metric: M2 to M160 \| Imperial: 1/4" to 6" (Custom non-standard sizes upon request)
Thread Configurations	UNC, UNF, UNEF, BSW, BSF, Metric Coarse (6g / 6H), Metric Fine, Pitch Roll Threads
Manufacturing Process	Cold Forging (M2 – M24), Hot Forging (M24 – M160), Precision CNC Machining & Thread Rolling
Raw Material Source	Prime quality billets from certified mills (Tata Steel, JSPL, Mukund Steel, Usha Martin)
Head Drive Styles	Hex Head, Heavy Hex, Square, Socket Cap (Six-Lobe / Allen), Slotted, Flange, Countersunk
Testing Certification	EN 10204 3.1 Mill Test Certificate, PED 97/23/EC, NACE MR0175 / ISO 15156, TUV/SGS 3rd Party Inspection

Material Grades & Exotic Alloy Specialization

Standard carbon steel bolting often fails when exposed to marine chloride attack, acid processing, or extreme thermal fatigue. Neelkamal Alloys LLP specializes in processing advanced alloy materials engineered for severe service:

Stainless Steel Bolts: Austenitic & Martensitic grades including SS 304, 304L, 316, 316L, 316Ti, 310S, 321, 347, 904L (ASTM A193 B8, B8M, B8T, Class 1 & Class 2).
Duplex & Super Duplex Steel Bolts: UNS S31803 / S32205 (Duplex 2205), UNS S32750 (Super Duplex 2507), UNS S32760 (Ferralium 255) offering high pitting resistance (PREN > 40).
Inconel & Nickel Alloy Bolts: Inconel 600, 601, 625, 718, Incoloy 800/825, Monel 400, Monel K500, Nickel 200/201 (ASTM B166, B446, B637).
Hastelloy & Specialty Alloys: Hastelloy C276, C22, B2, Alloy 20 (UNS N08020), SMO 254 for extreme acidic and chemical handling environments.
Titanium Bolts: Titanium Grade 2 (R50400) & Grade 5 Ti-6Al-4V (R56400) for aerospace weight reduction and sea-water immunity.

Protective Coatings & Surface Finishes

We provide high-performance surface treatments that dramatically improve corrosion life, prevent thread galling, and reduce friction coefficients during torque tightening:

Finish / Coating Type	Technical Characteristics & Key Applications
PTFE / Fluoropolymer / Xylan®	Provides extreme corrosion defense (1000+ hrs salt spray resistance) and anti-galling properties for offshore flange joint bolting.
Hot-Dip Galvanized (HDG)	Heavy zinc protection conforming to ASTM A153 / ISO 1461, ideal for outdoor infrastructure, solar structures, and transmission towers.
Bright Zinc Plated (BZP / Electro-zinc)	Available in Yellow, Black, Blue, and Clear passivations for indoor mechanical assembly and aesthetic automotive use.
Cadmium & Phosphate Coating	Offers smooth lubrication and salt water protection for military, aerospace, and marine hardware.
Dacromet & Geomet Coating	Non-electrolytic zinc flake coating providing high heat resistance and zero hydrogen embrittlement risk.

Rigorous Quality Assurance & E-E-A-T Testing Protocol

At Neelkamal Alloys LLP, product reliability is verified through rigorous quality control procedures at every phase of manufacturing. From raw material intake to final seaworthy export packing, our quality engineering team conducts:

100% PMI Testing: Positive Material Identification using handheld XRF analyzers to verify chemical composition before forging.
Mechanical Testing: Tensile strength, yield strength, elongation, area reduction, and Charpy V-notch impact testing at cryogenic and high temperatures.
Dimensional & Thread Inspection: Microscopic profile inspection, pitch gauge checks (Class 2A/3A & 6g tolerances), and optical comparator verifications.
Hardness Testing: Brinell (HBW), Rockwell (HRC/HRB), and Vickers (HV) scale verification ensuring compliance with ISO 898-1 property classes (8.8, 10.9, 12.9).
Third-Party Witness Inspection: We regularly facilitate inspection clearance by independent agencies including TUV, Bureau Veritas, SGS, DNV-GL, and Lloyd's Register.

Industrial Sectors Served & Global Supply Reach

Our precision bolts are specified by tier-1 engineering contractors, plant operators, and stocking distributors operating across demanding global industries:

Oil & Gas / Petrochemical Refineries: Subsea wellheads, offshore platforms, pressure vessel flanges, heat exchangers, and refinery piping systems.
Power Generation & Renewable Energy: Steam turbine casings, wind turbine tower structural joints, solar mounting arrays, and nuclear containment hardware.
Chemical Processing & Fertilizers: Reactor vessels, acid handling lines, urea synthesis towers, and chlorine scrubbers.
Heavy Construction & Infrastructure: Steel bridge structural connections, high-rise building anchor systems, and tunnel boring equipment.
Marine & Shipbuilding: Propulsion shafts, hull fittings, desalination plants, and seawater intake pumps.

Frequently Asked Questions (FAQ) for Procurement Managers

What bolt size range and dimensional standards does Neelkamal Alloys LLP produce?

We manufacture precision bolts from M2 to M160 in metric series and 1/4 inch to 6 inches in imperial series. Our production complies strictly with ASME B18.2.1, ASME B18.2.3.5M, DIN 931, DIN 933, ISO 4014, ISO 4017, and client-specific engineering drawings.

Which high-performance material grades are available for overseas industrial projects?

Our manufacturing program covers Stainless Steel (304/304L, 316/316L, 310S, 321, 347, 904L), Duplex & Super Duplex Steel (UNS S31803, S32205, S32750, S32760), Nickel Alloys (Inconel 600/625/718, Hastelloy C276/C22, Monel 400/K500, Alloy 20), Titanium (Grade 2, Grade 5), and High Tensile Carbon Steels.

What quality assurance and mill certification do you supply with export orders?

All export orders are delivered with authentic EN 10204 3.1 Mill Test Certificates. We perform 100% heat-number raw material verification, Positive Material Identification (PMI), mechanical tensile/yield testing, hardness testing, and accommodate third-party inspection (TUV, BV, SGS, DNV).

Can Neelkamal Alloys LLP supply custom-engineered bolts to drawing specifications?

Yes. Equipped with advanced CNC turning centers, multi-station cold headers, and hot forging presses, we produce specialized non-standard bolts, custom thread pitches, extended length bolts, and special head geometries to client drawings.