Silver Tubes is a well-established Fasteners Manufacturer in India, providing high-quality industrial fasteners with sophisticated production facilities and extensive global reach. As a prominent Fasteners Supplier based in Mumbai, we deal in custom fasteners, high-tensile bolts, nuts, and screws to suit different industrial purposes. Fastener plays a significant role in industries such as oil & gas, power, chemicals and construction by providing trustworthy joining solutions. Our fasteners come in different types, sizes, pressure ratings and grades of materials, meeting international and national quality standards such as ASME, ASTM, ISO and additional fastener standards. With ISO and PED certifications, we maintain strict quality control, testing and timely delivery, providing long-lasting and accurate fasteners at competitive price to satisfy global customer needs.
A fastener is defined as a mechanical device that joins or holds two or more objects together in such a way that they remain joined during their usage. Fasteners play very important roles in various industries, structures, automotive, construction, aerospace and manufacturing. We have recognized the role and shape of fasteners in providing safety and stability under a variety of loads and conditions. The performance and life span of the fasteners depend on the material chosen for the fasteners; stainless steel, alloy steel and brass are some examples. However, every industry requires resistance to corrosion, vibration, as well as temperature. With such high demands for sealing technologies with high-strength fasteners, it becomes imperative that industrial fastening solutions provide reliability along with long-term durability for assembled components.
Knowledge of the fasteners manufacturing process is vital for industries like construction, automobile, and aviation, where precision and strength are not negotiable. Advanced technologies such as CNC machining and robotic assembly are applied by modern fastener manufacturers to produce high-quality standard fasteners for critical applications. The manufacturing process includes several major steps that make high tensile bolts, nuts, screws, and custom fasteners perform well and be reliable.
This comprehensive process guarantees that all products—ranging from fasteners to high tensile bolts, nuts, screws provide better performance in even the most challenging conditions.
Our extensive offerings cover a variety of fields with industrial fasteners to meet many application needs.The fasteners include everything from simple nails and screws to bolts to specialty fasteners made from materials such as Hastelloy and SMO 254. Whether it be securing metal components or using high-performance fastener solutions for corrosive environments, our fasteners are strong, reliable, and easy to install.
Screws
Bolts
Nuts
Rivets
Washers
Nails
Anchors
Fastener suppliers in Mumbai; as will be considered leading, are capable of supplying fasteners in various prime materials and grades to suite diversified industrial needs.The selection of a particular fastener material has ensured the fastener to possess strength, corrosion resistance, and long-term serviceability.
Stainless Steel Fasteners
Stainless steel is one of the most commonly used materials for fasteners because it has excellent corrosion resistance, durability, and strength. It has a minimum content of 10.5% chromium, which creates a protective oxide layer and avoid rusting and oxidation. Stainless steel fasteners are often used in moisture, chemical and high-temperature environments.
Carbon Steel Fasteners
Carbon steel is an alloy of iron and carbon, which gives it strength and durability at a low cost. This material is used most extensively for such kinds of connectors because it offers high tensile strength at relatively low prices. It is prone without proper coating or treatment, carbon steel rusts and oxidizes quickly.
Alloy Steel Fasteners
Alloy steel is a type of carbon steel that contains other elements such as chromium, molybdenum, and vanadium to enhance strength, toughness and resistance to abrasion as well as heat.Such fasteners are used in very extreme environments and high-stress applications.
Monel Fasteners
Monel is a high-performance alloy, consisting of nickel and copper, that offers remarkable corrosion resistance in saltwater and acidic environments. Besides, it is highly durable and strong also resistant to oxidation and pitting; hence, ideally suited for extreme conditions.
Titanium Fasteners
Titanium is a high-strength but lightweight metal with excellent corrosion resistance. It is also non-magnetic, biocompatible and resistant to hostile temperatures, positioning it as an elite material in high-performance use.
Choosing the right material and grade helps ensure fastener reliability, safety, and longevity, even in the most demanding industrial conditions.
There are many fasteners for various uses, but others can be used anywhere in the key industries because of their reliability, strength, and simplicity in use.The following are the most popular fasteners and their common applications:
Screws
Screws are among the most versatile fasteners, used to join materials like wood, metal, and plastic. Self-tapping screws are especially valued in the metal fabrication industry for their ability to create threads during installation. They are commonly used in automotive, electrical, and light construction work.
Bolts
Bolts are strong, externally threaded fasteners designed for use with nuts. They provide high-strength connections in heavy-duty applications. Bolts are widely used in construction, infrastructure projects, and industrial machinery assembly.
Nuts
Nuts are internally threaded fasteners that pair with bolts to hold components securely. They are essential in the automotive, aerospace, and manufacturing industries where vibration-resistant fastening is required.
Rivets
Rivets are permanent mechanical fasteners ideal for joints that don’t require disassembly. They are heavily used in shipbuilding & marine, aircraft manufacturing, and structural applications where durability and vibration resistance are crucial.
Washers
Washers are flat discs placed under nuts or bolt heads to distribute load and prevent loosening. They are commonly used in industrial machines, electrical systems, and construction frameworks to protect surfaces and improve load distribution.
Nails
Nails are simple and quick-to-use fasteners used in woodworking, framing, and general carpentry. They are widely used in residential construction and light-duty projects due to their ease of application.
Anchors
Anchors are used to fix fasteners into concrete, masonry, or drywall surfaces. These are essential in the construction and infrastructure sectors, particularly for mounting structural elements, equipment, or fixtures onto walls or floors.
Each fastener type plays a critical role in supporting structural integrity and functionality across industries.
Below is a reference table showcasing standard metric and imperial sizes for bolts, nuts, washers and screws along with available grades and thickness options.
| Fastener Type | Nominal Size (Metric/Imperial) | Thread Pitch / TPI | Major Diameter | Minor Diameter | Typical Length Range | Reference Standards |
| Hex Bolt | M6 / 1/4" | 1.0 mm / ~20 TPI | 6 mm / 0.25" | ~4.5 mm / 0.177" | 10 – 100 mm / 3/8"–4" | ISO 4014, ASTM A325 |
| Hex Bolt | M8 / 5/16" | 1.25 mm / ~18 TPI | 8 mm / 0.313" | ~6.0 mm / 0.236" | 12 – 150 mm / 1/2"–6" | ISO 4014, ASTM A325 |
| Hex Bolt | M10 / 3/8" | 1.5 mm / ~16 TPI | 10 mm / 0.375" | ~7.5 mm / 0.295" | 16 – 200 mm / 3/4"–8" | ISO 4014, ASTM A325 |
| Machine Screw | M6 / 1/4" | 0.75–1.0 mm (varies) | 6 mm / 0.25" | ~4.5 mm | 6 – 80 mm | ISO 4762, ASTM F593 |
| Wood Screw | 1/4" (common) | Coarse (for grip) | 1/4" | Varies with point | 1" – 4" | ANSI; Proprietary |
| Nut | M6 / 1/4" | Matches bolt pitch | (Fastener’s nominal diameter) – (across flats ~10 mm) | N/A | Standard thickness | ISO 4032, ASTM A563 |
| Washer | For M6 / 1/4" fasteners | – | Inner Dia: ~6 mm; Outer Dia: ~12 mm | N/A | Thickness: 1–2 mm | ISO 7089, ASTM F228
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Fastener specifications define the key mechanical, dimensional, and material properties that ensure their performance in demanding industrial applications.
| Fastener Type | Material | Dimensions (Diameter / Length / Thread Pitch) | Grade | Coating Options | Standards (ASTM/ASME/ISO/DIN/ANSI) | Tensile Strength (MPa) | Yield Strength (MPa) | Typical Applications |
| Hex Bolts | Carbon Steel, Alloy Steel | M6–M64 / 10–300mm / 1.0–3.5mm | 4.6, 8.8, 10.9, 12.9 | Zinc plated, HDG, Black Oxide | ASTM A325, ISO 898-1, DIN 931/933, ASME B18.2.1 | 400–1220 | 240–1100 | Construction, bridges, steel structures |
| High-Tensile Bolts | Alloy Steel | M10–M100 / 25–300mm / Fine & Coarse threads | 8.8, 10.9, 12.9 | Black Oxide, Zinc, Phosphate | ASTM A490, ISO 898-1, DIN 6914 | 830–1220 | 660–1100 | Heavy machinery, automotive, structural steel |
| Self-Tapping Screws | SS 304, 316, 410 | 3mm–12mm / 10–100mm / Self-cutting thread | A2, A4 | SS Finish, Zinc, Ruspert | ISO 1479, DIN 7982, ANSI B18.6.4 | 500–700 | 200–450 | Sheet metal, ducting, light fabrication |
| Socket Head Cap Screws | Alloy Steel | M3–M36 / 10–200mm / 0.5–3.0mm | 12.9 | Black Oxide, Zinc | ASTM A574, ISO 4762, DIN 912 | ≥1220 | ≥1100 | Aerospace, robotics, precision machines |
| Nuts (Hex, Heavy Hex) | Carbon Steel, SS 304/316 | M6–M100 / 1/4"–4" (Standard/Coarse/Fine) | Grade 2H, A194 Gr. 8 | Plain, Zinc, Galvanized, PTFE | ASTM A563, A194, ASME B18.2.2, DIN 934 | 600–1000 | 400–800 | Bolt assemblies, pipelines, flange joints |
| Washers (Flat, Spring) | Carbon Steel, SS 304/316 | ID: 3mm–100mm / OD: 6mm–120mm / Thickness: 1–6mm | F436, A2, A4 | Plain, Zinc, HDG | ASTM F436, ISO 7089, DIN 125 | N/A | N/A | Load distribution, anti-loosening, vibration control |
| Stud Bolts | Alloy Steel (B7, B8, B8M) | M8–M100 / 50–1000mm / 1.25–3.0mm Pitch | ASTM A193 B7/B8 | Teflon, Galvanized, PTFE | ASTM A193/A194, ASME B16.5, B18.31.2 | 860–1000 | 690–830 | Flanged connections, pressure vessels |
| Anchor Bolts | Mild Steel, SS, Alloy Steel | M10–M64 / 100–1000mm / Custom thread | 4.6, 8.8 | Galvanized, Epoxy, Zinc | ASTM F1554, DIN 529, ISO 898-1 | 400–900 | 250–640 | Foundation anchoring, concrete supports |
| Threaded Rods | SS 304/316, B7, B8 | M6–M100 / up to 3 meters / Full thread | ASTM A193, A307 | Plain, Zinc, PTFE | DIN 975, ASTM A193, ISO 898 | 600–1000 | 400–800 | Suspension systems, bracing, general fastening |
Understanding the chemical composition of fasteners is essential to ensure their strength, corrosion resistance, and long-term durability in demanding applications.
| Material Type | Grade / Spec | C (%) | Mn (%) | Cr (%) | Ni (%) | Mo (%) | P (%) | S (%) | Notes |
| Carbon Steel | ASTM A307 (Grade A/B) | 0.12–0.30 | 0.60–1.65 | — | — | — | ≤ 0.04 | ≤ 0.05 | General-purpose bolts |
| Alloy Steel | ASTM A193 B7 | 0.37–0.49 | 0.65–1.10 | 0.75–1.20 | — | 0.15–0.25 | ≤ 0.035 | ≤ 0.040 | High-temp, pressure systems |
| Stainless Steel | ASTM A193 B8 (304) | ≤ 0.08 | ≤ 2.00 | 18.0–20.0 | 8.0–11.0 | — | ≤ 0.045 | ≤ 0.030 | Corrosion-resistant |
| ASTM A193 B8M (316) | ≤ 0.08 | ≤ 2.00 | 16.0–18.0 | 10.0–14.0 | 2.0–3.0 | ≤ 0.045 | ≤ 0.030 | Marine & chemical use | |
| High Strength | ISO 898-1 Grade 8.8 | ≤ 0.35 | 0.50–0.90 | — | — | — | ≤ 0.035 | ≤ 0.035 | Structural bolts |
| ISO 898-1 Grade 10.9 | ≤ 0.40 | 0.50–0.90 | — | — | — | ≤ 0.035 | ≤ 0.035 | High tensile strength | |
| ISO 898-1 Grade 12.9 | ≤ 0.45 | 0.50–0.90 | — | — | — | ≤ 0.035 | ≤ 0.035 | Very high strength |
Below is a table highlighting the key mechanical properties of mechanical fasteners, including tensile strength, yield strength, and hardness, which define their performance in various applications.
| Mechanical Property | Tensile Strength Ranking | 3.6 | 4.6 | 4.8 | 5.6 | 5.8 | 6.8 | 8.8 (1) | 9.8 (2) | 10.9 | 12.9 |
| Nominal Tensile Strength Rm and nom N/mm² | 300 | 400 | 500 | 500 | 600 | 800 | 800 | 900 | 1000 | 1200 | |
| Minimum Tensile Strength Rm and min(4) N/mm² | 330 | 420 | 520 | 600 | 800 | 830 | 900 | 900 | 1040 | 1220 | |
| Vickers Hardness HV F=98N | Min. | 95 | 120 | 130 | 155 | 160 | 250 | 255 | 290 | 320 | 385 |
| Max. | 220(5) | 250 | 250 | 320 | 335 | 360 | 380 | 380 | 380 | 435 | |
| Brinell Hardness HB F=30D²/0.102 | Min. | 90 | 114 | 124 | 147 | 152 | 181 | 238 | 242 | 276 | 304 |
| Max. | 209(5) | 238 | 238 | 304 | 318 | 342 | 361 | 366 | 366 | 414 | |
| Rockwell Hardness | Min. (HRB) | 52 | 67 | 71 | 77 | 79 | 82 | 89 | - | - | - |
| Min. (HRC) | - | - | - | - | - | - | 22 | 23 | 28 | 39 | |
| Max. (HRB) | 95.0(5) | - | - | - | - | 99.5 | - | - | - | - | |
| Max. (HRC) | - | - | - | - | - | - | 32 | 34 | 37 | 44 | |
| Surface Hardness HV0.3 | Max. | - | - | - | - | - | - | - | (8) | - | - |
| Lower Yield Point Re (7) N/mm² | Nominal Diameter | 180 | 240 | 320 | 300 | 400 | 480 | - | - | - | - |
| Min. | 190 | 240 | 340 | 300 | 420 | 480 | - | - | - | - | |
| 0.2% Durability RP0.2 (8) N/mm² | Nominal Diameter | - | - | - | - | - | - | 640 | 640 | 720 | 900 |
| Min. | - | - | - | - | - | - | 660 | 720 | 940 | 1100 | |
| Guarantee Load Stress Sp | Sp/ReL or Sp/RP0.2 | 0.94 | 0.94 | 0.91 | 0.93 | 0.9 | 0.92 | 0.91 | 0.91 | 0.88 | 0.88 |
| Rupture Elongation % | 25 | 22 | - | - | 12 | 12 | 10 | 9 | 8 | 8 |
ASTM, DIN, and ASME are international and national quality benchmarks that define the manufacturing, mechanical, and dimensional standards for fasteners. Each standard impacts the fastener quality, performance, and their suitability for specific industrial applications.
ASTM Fastener Standards
The American Society for Testing and Materials (ASTM) sets technical standards for materials and products, including fasteners, widely used across North America and globally. These fasteners are preferred in industries like oil & gas, power generation, petrochemical, and construction due to their high-temperature and pressure resistance, toughness, and corrosion resistance.
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B7 is an alloy steel fastener used in high-temperature and high-pressure services; B8 is stainless steel, ideal for corrosion resistance. Common in oil & gas, chemical, and power industries.
ASTM A320
Specifies low-temperature service fasteners. Frequently used in cryogenic environments like LNG processing and refrigeration systems.
ASTM A325
Covers structural bolts used in steel-to-steel connections. Widely used in bridges, buildings, and construction frameworks.
DIN Fastener Standards
DIN (Deutsches Institut für Normung) is the German national standard, widely accepted across Europe and globally in mechanical and automotive engineering. They are commonly used in automotive, mechanical engineering, construction, and manufacturing due to their strict tolerances and consistent quality.
DIN 933
Hex head full-threaded bolts for general-purpose use. Applied in machinery, automotive, and construction industries.
DIN 934
Hex nuts for use with bolts and screws. Known for dimensional accuracy and reliability across mechanical and engineering applications.
DIN 931
Hex bolts with partially threaded shanks. Ideal for structural assembly where alignment is critical, like heavy machinery.
DIN 912
Socket head cap screws for high-strength fastening in limited space. Common in aerospace, robotics, and automotive applications.
ASME Fastener Standards
The American Society of Mechanical Engineers (ASME) defines mechanical engineering standards used primarily in North America and in heavy industries around the world. ASME fastener are extensively used in heavy equipment, marine, construction, and industrial machinery.
ASME B18.2.1
Covers square and hex bolts for general mechanical applications. Preferred in construction and heavy equipment sectors.
ASME B18.3
Details socket head cap screws and shoulder bolts. Often used in machine assembly and tooling industries.
ASME B18.6.3
Defines dimensions for machine screws and tapping screws. Widely used in electronics, sheet metal, and small-scale assembly.
Each of these standards ensures compatibility, safety, and performance, depending on the environment and industry application. Selecting the right standard helps maintain structural integrity and compliance across global markets.
As trusted fasteners suppliers in Mumbai, we are committed to delivering superior quality and reliability across every order. Our fasteners are manufactured under strict quality control systems and backed by international certifications like ISO and PED. We offer custom fasteners, high-tensile bolts, and precision-engineered nuts to meet specific industrial needs. With a global supply network, competitive pricing, and free delivery, we ensure timely service without compromising on performance or safety. Our dedicated support team, comprehensive product warranty, and robust safety measures make us a preferred choice for industries demanding consistency and excellence. Whether for bulk orders or specialized components, we guarantee precision, durability, and total customer satisfaction.
Construction Industry
Fasteners are extensively used in the construction industry for securing structural elements like steel beams, bridges, and concrete anchors. Common fasteners include anchor bolts, structural bolts, washers, and nuts. These must comply with global standards such as ASTM, ISO, and DIN. Popular grades used are ASTM A325, A490, DIN 931, and ISO 4014, which offer excellent load-bearing strength and durability in structural applications.
Automotive Industry
In the automotive sector, fasteners like high-tensile bolts, nuts, and self-tapping screws are critical for assembling engines, body frames, and interiors. These fasteners need to withstand vibration, heat, and dynamic stress, hence conforming to ASME, SAE, and ISO standards. Popular grades include SAE J429 Grade 5, Grade 8, and ISO 898-1, known for high strength and performance.
Aerospace Industry
Aerospace fasteners such as aircraft bolts, self-locking nuts, and rivets are used in both structural and non-structural aircraft components. These fasteners must meet stringent safety and performance standards like AS9100, NAS, and MIL-SPEC. Popular grades include NAS 1580, MIL-DTL-1222, and ASME B18.3, offering lightweight construction with high tensile strength and corrosion resistance.
Oil & Gas Industry
The oil and gas industry uses fasteners like stud bolts, hex bolts, washers, and flange fasteners in high-pressure and corrosive environments. These are manufactured as per ASTM, ASME, and API standards to ensure safety and durability in pipelines, rigs, and refineries. Popular grades include ASTM A193 B7, B16, and API 20E.
Marine Industry
Marine environments demand fasteners that resist corrosion from saltwater and humidity. Common fasteners include stainless steel bolts and titanium fasteners, widely used in shipbuilding, offshore platforms, and marine engines. These fasteners comply with ASTM and ISO standards, with popular grades like ASTM F593, F594, and Titanium Grade 5 ensuring superior corrosion resistance and strength.
Power Plants
Fasteners in power generation, especially thermal and nuclear plants, must withstand extreme heat and pressure. High-pressure bolts, nuts, and washers are essential for turbines, boilers, and reactors. These are designed to meet ASME and ASTM standards, with popular grades like ASTM A194, A320, and ASME SA-193 offering high performance under critical conditions.
India is home to many top-tier fastener manufacturers, but the best ones stand out due to their quality, certifications, custom solutions, and global supply capability. Reputed names offer high-tensile bolts, nuts, screws, and custom fasteners that meet international standards like ASTM, ASME, DIN, and ISO.
Fasteners are essential mechanical components that hold structures and equipment together, ensuring safety, strength, and durability. They are critical in industries like construction, automotive, aerospace, and oil & gas, where structural integrity and long-term performance matter most.
In India, commonly used fasteners include bolts, nuts, washers, screws, and rivets. These are widely applied across infrastructure, automobile, machinery, and electrical industries, often made from stainless steel, carbon steel, and alloy steel for durability and cost-effectiveness.
Common fastener head styles include hex head, pan head, flat head, round head, and socket head. Each head type is selected based on the application’s load requirement, space limitations, and tool compatibility, making them suitable for varied industrial and structural tasks.
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