Stanley Alloys – Stainless Steel Machine Screws
Introduction
At Stanley Alloys, we specialize in manufacturing and supplying high-quality stainless steel machine screws engineered for precision fastening. Designed for durability, strength, and corrosion resistance, our screws are trusted across industries such as automotive, marine, aerospace, construction, petrochemical, and general engineering.
About Stainless Steel Machine Screws
Stainless steel machine screws are precision-engineered fasteners designed to provide secure and reliable connections in a wide range of industrial, automotive, marine, and construction applications. Unlike conventional screws, machine screws feature uniform threads along their entire shaft and are intended for use with pre-tapped holes or nuts, ensuring a tight and vibration-resistant fastening.
At Stanley Alloys, our stainless steel machine screws are manufactured using premium-grade stainless steel including 304, 316, 316L, 410, and specialty alloys like 2205 Duplex and A193 B8M. This ensures exceptional strength, durability, and corrosion resistance, even in extreme environments such as offshore, chemical, and high-temperature industrial settings.
Key Specifications
- Size Range:
Inch: #4 – 5/16"
Metric: M3 – M8 - Length Range: 1/4" – 6" (6.35 mm – 150 mm)
- Head Types Available:
Industrial Hex Washer Head, Round Washer Head, Pan Head, Hex Socket Head, Cheese Head, Flat Head, Truss Washer Head, Truss Head, Oval Head - Thread Types: UNC, UNF, CA (Soft), TRI-POINT
- Standards: IFI, ANSI, ASTM, ISO, DIN, JIS, BS & AS, including special requests per customer drawings
Key Features & Benefits
- Excellent corrosion resistance in harsh environments
- High mechanical strength and reliability
- Compatibility with nuts, washers, and threaded holes
- Designed for vibration and impact resistance
- Long service life with minimal maintenance
Applications
- Automotive & Transport – Engines, body panels, safety systems
- Marine & Offshore – Saltwater-resistant fastening for ships, rigs, and coastal structures
- Electronics & Electricals – Panels, enclosures, PCBs, and assemblies
- Construction & Infrastructure – HVAC, metal structures, pipelines, and supports
- Aerospace & Defense – Lightweight yet durable fastening solutions
- Industrial Machinery – Pumps, compressors, turbines, and heavy equipment
Types We Supply
- Pan Head Machine Screws
- Flat Head / Countersunk Machine Screws
- Round Head Machine Screws
- Truss Head Machine Screws
- Hex Head Machine Screws
- Socket Head Cap Screws
Stainless Steel Machine Screw Sizes
Overview
At Stanley Alloys, we offer a comprehensive range of stainless steel machine screws in coarse, fine, and extra-fine thread profiles to meet diverse requirements of industrial, automotive, marine, and construction applications. Manufactured to international standards (DIN, ISO, ASTM, JIS, ANSI, BS), our screws ensure high performance, corrosion resistance, and dimensional accuracy.
Coarse Threads
UNC / Metric Coarse threads are ideal for general fastening applications, providing faster assembly and greater resistance to cross-threading.
Fine Threads
UNF / Metric Fine threads offer higher tensile strength and better fatigue resistance, suitable for precision assemblies.
Extra Fine Threads
Designed for applications requiring extremely tight tolerances, precise adjustment, and vibration resistance.
Standard Metric Sizes of Stainless Steel Machine Screws
| Screw Size | Coarse Thread (mm) | Fine Thread (mm) | Extra Fine Thread (mm) |
|---|---|---|---|
| M1.4 | 0.3 | – | – |
| M2 | 0.4 | – | – |
| M2.5 | 0.45 | – | – |
| M3 | 0.5 | – | – |
| M3.5 | 0.6 | – | – |
| M4 | 0.7 | – | – |
| M5 | 0.8 | – | – |
| M6 | 1.0 | – | – |
| M7 | 1.0 | – | – |
| M8 | 1.25 | 1.0 | – |
| M10 | 1.5 | 1.25 | 1.0 |
| M12 | 1.75 | 1.5 | 1.25 |
| M14 | 2.0 | 1.5 | – |
| M16 | 2.0 | 1.5 | – |
| M18 | 2.5 | 1.5 | – |
| M20 | 2.5 | 1.5 | – |
| M22 | 2.5 | – | – |
| M24 | 3.0 | 2.0 | – |
| M30 | 3.5 | – | – |
| M36 | 4.0 | – | – |
Note: Custom sizes and thread profiles are available on request, including non-standard metric and inch threads.
Why Proper Machine Screw Size Matters
- Secure fastening without thread stripping or loosening
- Optimal load-bearing capacity and mechanical performance
- Corrosion resistance and longevity in harsh environments
- Precision alignment in machinery, electronics, and structural assemblies
Stanley Alloys Advantage
- Wide range: M1.4 up to M160 and custom diameters
- All thread profiles: Coarse, Fine, Extra Fine
- Premium grades: 304, 316, 316L, 2205 Duplex, A193 B8M
- Global Standards: DIN, ISO, ASTM, JIS, ANSI, BS, IS
- Custom Solutions: CNC machining, hot forging, cold forming
Stainless Steel Machine Screws
Stanley Alloys – Precision Fasteners Manufacturer & Supplier in India
Looking for premium ASTM A193 Grade B8 Small or Extra Long Torx Machine Screws in India? Stanley Alloys is a trusted manufacturer and supplier of high-tensile stainless steel machine screws in M4, M5, M6, M8, and other assorted sizes. Our precision-engineered fasteners are designed to meet global standards and cater to industrial, automotive, marine, and construction applications.
Overview
Machine screws are threaded fasteners used for precise metal-to-metal or metal-to-plastic connections. Unlike self-tapping screws, they require pre-tapped holes or nuts for secure fastening. At Stanley Alloys, we specialize in DIN, JIS, ISO, ASTM, ANSI, and custom machine screws, offering high corrosion resistance, superior mechanical strength, and consistent performance.
Manufacturing & Size Range
Processes
- Cold Forming Process: M2 – M24
- Hot Forging Process: M24 – M100 (up to 1,100 mm length)
- CNC Machining: M100 / 4” Dia, up to 1,500 mm length
Sizes
- Available Metric Sizes: M2 – M160, including custom requirements
- Available Inch Sizes: 1/2" – 4" diameter, 1/2" – 52" length
Material Grades
Stainless Steel
- 304, 316, 316L, 2205, 410, 431, 416, 440C, 18-8
- A2, A4, A193 B8M/B8/B7/B6
Carbon & Alloy Steel
- A193 Grade B7, A320 L7
- SCM435, C10B21, C10B33, ASTM A193 Grade B16
- High Tensile: 8.8, 10.9, 12.9
Other Metals
- Brass, Bronze, Aluminum, Titanium
Surface Finish & Treatment
- Zinc (yellow, blue, white, black)
- Black Oxide
- Dacroment
- Anodizing
- PTFE Coating
- Hot Dip Galvanized
- Sherardized
- Electroless Nickel, Geomet & Custom Coatings
- Passivation as per ASTM A380/A380M
- Rust preventive oils, polish, sandblasting, heat treatment
Thread Standards & Tolerances
- UNC, UNF, UNEF, NPT, UNJC, UNJF, UNK, UNR
- ISO metric tolerances: +/-0.01 mm to +/-0.05 mm
- Fully threaded up to 6" as per ASME B18.6.3
- Compatible with DIN, JIS, BS, ANSI, IS, ASME, ISO, GB, UNI, CSN, EU standards
Packaging & Delivery
- Pallet, carton, wooden crate packing available
- MOQ: 100 pieces
- Custom packaging on request
- Port of dispatch: Mumbai / Kalamboli, Maharashtra, India
Quality & Certification
- Manufacturer Test Certificate (MTC) as per EN 10204 / 3.1
- Tensile & Hardness Testing: ISO 898-1 & ISO 6508-1
- Calibrated gauges for thread & preload verification
- Tri-Roll thread comparators
- Free pre-production samples available
Why Choose Stanley Alloys?
Stainless Steel Machine Screw Materials & Grades
Overview
At Stanley Alloys, we offer an extensive range of stainless steel machine screws, crafted from premium materials to meet global industrial standards. Our screws are engineered for strength, corrosion resistance, precision, and reliability across automotive, marine, aerospace, construction, and industrial applications.
We supply machine screws in various head types, lengths, and thread profiles, all conforming to international standards such as DIN, ISO, ASTM, JIS, ANSI, and BS. Our high-quality material grades ensure long-lasting performance even in demanding environments.
Austenitic Stainless Steel
- 304 – General-purpose, corrosion-resistant.
- 304L – Low carbon, improved weldability.
- 316 – Superior corrosion resistance, marine applications.
- 316L – Low carbon, high-temperature applications.
- 317L – Enhanced corrosion resistance for chemical processing.
- 321 – Stabilized for high-temperature resistance.
- 904L – High-alloy, extreme corrosion environments.
Ferritic & Martensitic Stainless Steel
- 410 – High hardness, moderate corrosion resistance.
- A193 B6 (410) – High-strength heat-treated ferritic screw.
Duplex & Precipitation-Hardened
- Duplex 2205 – High strength + corrosion resistance, offshore/chemical.
- 17-4 PH – High-strength, corrosion-resistant, aerospace/structural.
High-Grade ASTM Machine Screws
- ASTM A193 B7m – Medium-carbon alloy, quenched & tempered.
- ASTM A193 B8 – Austenitic stainless steel, superior corrosion resistance.
- ASTM A193 B8M – Metric austenitic stainless steel, high-pressure applications.
- ASTM A193 B8T (321) – Stabilized stainless steel for elevated temperatures.
- ASTM A193 B8C (347) – Corrosion-resistant austenitic steel.
- ASTM A193 B6 (410) – High-strength ferritic steel.
Metric & Mechanical Grades
- A2 – Standard corrosion-resistant stainless steel.
- A2-70 – Heat-treated for higher tensile strength.
- A4 – Marine-grade stainless steel.
- A4-70 & A4-80 – High-strength marine-grade.
- 8.8 & 4.8 – Carbon steel, high tensile strength.
Machine Screw Types
- Hex Head – High-torque applications.
- Pan Head / Phillips Pan Head (DIN 7985a) – Rounded top, general-purpose.
- Flat Head – Countersunk, flush mounting.
- Slotted Cheese / Round Head – Light-duty applications.
- Torx – High-torque, tamper-resistant.
- Truss Head – Wide, low-profile, sheet metal fastening.
- Extra Long Screws – For extended-length assemblies.
Precision Testing & Inspection Tools
- Micrometer – Diameter & thread pitch measurement.
- Smooth Plug Gauge & Thread Gauge – Thread integrity verification.
- Coordinate Measuring Machine (CMM) – 3D dimensional verification.
- Roughness Tester – Surface finish inspection.
- Image Measuring Instrument – Optical verification of threads & geometry.
- Routine Caliper Inspection – Ensures tight tolerance compliance.
Machine Screw DIN Standards & Torque Guide
Overview
At Stanley Alloys, we manufacture and supply high-quality stainless steel machine screws that conform to DIN standards, ensuring precision, reliability, and compatibility across industrial, automotive, marine, and construction applications. Understanding the DIN standard, head type, and torque values is essential for proper assembly, optimal load distribution, and long-term performance.
Our screws are engineered using premium stainless steel grades like 304, 316, 316L, A193 B8M, providing corrosion resistance, high tensile strength, and durability in all environments.
DIN Standard Machine Screws
| DIN No. | Description |
|---|---|
| DIN 84 | Slotted Cheese Head Machine Screw |
| DIN 85 | Slotted Pan Head Machine Screw |
| DIN 439B | Machine Screw Hex Nut, Finished Hex Jam Nut |
| DIN 963 | Slotted Flat Head Machine Screw |
| DIN 964 | Slotted Oval Head Machine Screw |
| DIN 965 | Phillips Flat Head Machine Screw |
| DIN 966 | Phillips Oval Head Machine Screw |
| DIN 7985 | Phillips Pan Head Machine Screw |
Note: Stanley Alloys produces these DIN-standard screws in both metric and inch sizes, with precise thread tolerances and customizable lengths to suit your project requirements.
Torque for Small to Medium Machine Screws (in-lbs)
| Machine Screw Size | 18-8 SS | 316 SS | Silicon Bronze | Monel | Brass | 2024-T4 Aluminum |
|---|---|---|---|---|---|---|
| 4-40 | 5.2 | 5.5 | 4.8 | 5.3 | 4.3 | 2.9 |
| 4-48 | 6.6 | 6.9 | 6.1 | 6.7 | 5.4 | 3.6 |
| 5-40 | 7.7 | 8.1 | 7.1 | 7.8 | 6.3 | 4.2 |
| 5-44 | 9.4 | 9.8 | 8.7 | 9.6 | 7.7 | 5.1 |
| 6-32 | 9.6 | 10.1 | 8.9 | 9.8 | 7.9 | 5.3 |
| 6-40 | 12.1 | 12.7 | 11.2 | 12.3 | 9.9 | 6.6 |
| 8-32 | 19.8 | 20.7 | 18.4 | 20.2 | 16.2 | 10.8 |
| 8-36 | 22.0 | 23.0 | 20.4 | 22.4 | 18.0 | 12.0 |
Torque for Larger Machine Screws & Bolts (ft-lbs)
| Bolt Size | 18-8 SS | 316 SS | Silicon Bronze | Monel | Brass | 2024-T4 Aluminum |
|---|---|---|---|---|---|---|
| 1/2-13 | 43 | 45 | 40 | 48.7 | 35.2 | 26 |
| 1/2-20 | 45 | 47 | 42 | 51 | 37 | 27 |
| 9/16-12 | 56 | 59 | 53 | 65 | 47 | 34 |
| 9/16-18 | 62 | 65 | 58 | 71 | 51 | 38 |
| 5/8-11 | 92 | 96 | 86 | 111 | 76 | 60 |
| 5/8-18 | 103 | 108 | 96 | 123 | 85 | 67 |
| 3/4-10 | 127 | 131 | 118 | 153 | 104 | 82 |
| 3/4-16 | 124 | 129 | 115 | 149 | 102 | 80 |
| 7/8-9 | 194 | 202 | 178 | 231 | 159 | 124 |
| 7/8-14 | 193 | 201 | 177 | 230 | 158 | 124 |
| 1-8 | 286 | 299 | 265 | 344 | 235 | 184 |
| 1-14 | 259 | 270 | 240 | 311 | 212 | 166 |
Why Torque and DIN Compliance Matter
- Optimal Joint Strength: Prevents loosening and thread stripping.
- Material-Specific Torque Values: Different materials require specific torque for safe assembly.
- Global Standard Compliance: DIN-certified screws ensure compatibility with international equipment and components.
- Industrial Versatility: Suitable for automotive, aerospace, marine, electronics, and heavy machinery.
Stainless Steel Machine Screw Diameters & Sizes
Overview
At Stanley Alloys, we provide a wide range of stainless steel machine screws in both metric and inch sizes, engineered for precision, durability, and global compliance. Understanding the nominal thread diameter and proper sizing is critical for achieving secure, vibration-resistant fastening in industrial machinery, automotive components, marine hardware, and construction applications.
All measurements are in accordance with ASME B18.6.3 standards, ensuring accurate fit, thread engagement, and compatibility with nuts and tapped holes.
Standard Machine Screw Diameters
| Size | Nominal Thread Diameter (Decimal) | Nearest Fractional |
|---|---|---|
| #0 | 0.060" | 1/16" |
| #1 | 0.073" | 5/64" |
| #2 | 0.086" | 3/32" |
| #3 | 0.099" | 7/64" |
| #4 | 0.112" | 7/64" |
| #5 | 0.125" | 1/8" |
| #6 | 0.138" | 9/64" |
| #8 | 0.164" | 5/32" |
| #10 | 0.190" | 3/16" |
| #12 | 0.216" | 7/32" |
Metric vs Inch Machine Screw Size Equivalents
| Metric Machine Screw | Inch Machine Screw Equivalent |
|---|---|
| M1.4-0.3 | 0-80 (Larger) |
| M2-0.4 | 1-64 (Smaller) |
| M2.5-0.45 | 3-56 (Larger) |
| M3-0.5 | 4-48 (Smaller) |
| M3.5-0.6 | 6-40 (Same) |
| M4-0.7 | 8-36 (Larger) |
| M5-0.8 | 10-32 (Smaller) |
| M6-1.0 | 1/4-28 (Larger) |
| M7-1.0 | 1/4-28 (Smaller) |
| M8-1.25 | 5/16-18 (Smaller) |
| M10-1.5 | 3/8-16 (Smaller) |
| M12-1.75 | 1/2-13 (Larger) |
| M14-2.0 | 9/16-12 (Larger) |
| M16-2.0 | 5/8-11 (Smaller) |
| M18-2.5 | 3/4-10 (Larger) |
| M20-2.5 | 3/4-10 (Smaller) |
| M22-2.5 | 7/8-9 (Larger) |
| M24-3.0 | 1-8 (Larger) |
| M30-3.5 | 1 1/8-7 (Smaller) |
| M36-4.0 | 1 3/8-6 (Smaller) |
Importance of Correct Screw Diameter
- Secure fastening and proper thread engagement
- Optimal load distribution for mechanical strength
- Compatibility with nuts, tapped holes, and washers
- Long-term corrosion resistance and durability
Stanley Alloys Advantage
- Comprehensive Range: Metric sizes M1.4–M36 and inch sizes #0–1 3/8”
- Premium Stainless Steel Grades: 304, 316, 316L, 410, 2205 Duplex, A193 B8M, and more
- Custom Manufacturing: CNC machining, cold forming, and hot forging
- Global Standards Compliance: DIN, ISO, ASTM, ANSI, JIS, BS, IS
- Applications Across Industries: Automotive, aerospace, marine, electronics, construction, industrial machinery
Applications
- Industrial machinery assembly and tooling
- Automotive engines, chassis, and precision components
- Marine hardware for saltwater environments
- Construction and structural frameworks
- Electronics enclosures and control panels
Machine Screw Thread Pitch & Threads Per Inch (TPI)
Overview
Precision is critical when selecting machine screws, and understanding the thread pitch and threads per inch (TPI) is essential for secure, vibration-resistant fastening. At Stanley Alloys, we provide a comprehensive range of stainless steel machine screws with accurately engineered threads for industrial, automotive, marine, and construction applications.
Thread pitch determines the distance between adjacent threads, while threads per inch (TPI) indicate the number of threads in a one-inch length of the screw. Choosing the correct combination ensures mechanical strength, precise assembly, and optimal load distribution.
Machine Screw Thread Pitch vs Threads Per Inch
| Pitch (mm) | Pitch (inches) | Threads Per Inch (TPI) |
|---|---|---|
| 0.2 | 0.0079 | 127.00 |
| 0.25 | 0.0098 | 101.60 |
| 0.3 | 0.0118 | 84.67 |
| 0.35 | 0.0138 | 72.57 |
| 0.4 | 0.0157 | 63.50 |
| 0.45 | 0.0177 | 56.44 |
| 0.5 | 0.0197 | 50.80 |
| 0.6 | 0.0236 | 42.33 |
| 0.7 | 0.0276 | 36.29 |
| 0.75 | 0.0295 | 33.87 |
| 0.8 | 0.0315 | 31.75 |
| 1.0 | 0.0394 | 25.40 |
| 1.25 | 0.0492 | 20.32 |
| 1.5 | 0.0591 | 16.93 |
| 1.75 | 0.0689 | 14.51 |
| 2.0 | 0.0787 | 12.70 |
| 2.5 | 0.0984 | 10.16 |
| 3.0 | 0.1181 | 8.47 |
| 3.5 | 0.1378 | 7.26 |
| 4.0 | 0.1575 | 6.35 |
| 4.5 | 0.1772 | 5.64 |
| 5.0 | 0.1969 | 5.08 |
| 5.5 | 0.2165 | 4.62 |
| 6.0 | 0.2362 | 4.23 |
Fine Threads
Higher TPI, smaller pitch – increased tensile strength and fatigue resistance, ideal for precision assemblies and high-stress applications.
Coarse Threads
Lower TPI, larger pitch – faster assembly, better resistance to cross-threading, suitable for general-purpose fastening.
Extra-Fine Threads
Extremely tight pitch – used where precise adjustment, high vibration resistance, or very fine tensioning is required.
Why Thread Accuracy Matters
- Mechanical reliability: optimal load distribution and prevents loosening
- Global standards compliance: DIN, ISO, ANSI, ASTM, BS, JIS, custom requirements
- Custom applications: CNC machining, precision forging for special thread profiles
- Wide range: from M1.4 screws to large M160 or 4" diameter screws
Applications
- Industrial machinery & equipment assembly
- Automotive engine components & chassis fastening
- Marine and offshore hardware
- Construction & structural connections
- Electronics, electrical enclosures, and precision devices
Coarse & Fine Thread Stainless Steel Machine Screws
Overview
At Stanley Alloys, we manufacture and supply high-precision stainless steel machine screws with both coarse and fine thread profiles, designed to meet international standards and industrial requirements. Proper selection of thread type, pitch, and size is critical for achieving secure fastening, optimal load distribution, and long-lasting performance in machinery, automotive, marine, and construction applications.
Our machine screws are available in metric and inch sizes, with thread specifications engineered to international standards (DIN, ISO, ANSI, ASTM, JIS, BS). Whether you require high-strength coarse threads for general fastening or fine threads for precision assemblies, Stanley Alloys provides solutions tailored to your exact requirements.
Coarse & Fine Thread Machine Screws – Size, Pitch, and TPI
| Size | Series | Thread Type | Pitch (inches) | Threads per Inch (TPI) |
|---|---|---|---|---|
| M14-2.0 | Metric | Coarse | 0.079 | 12.7 |
| 9/16-12 | Inch | Coarse | 0.083 | 12 |
| M14-1.5 | Metric | Fine | 0.059 | 16.9 |
| 9/16-18 | Inch | Fine | 0.056 | 18 |
| M3.5-0.6 | Metric | Coarse | 0.024 | 42.3 |
| 6-32 | Inch | Coarse | 0.031 | 32 |
| M3.5-0.35 | Metric | Fine | 0.014 | 72.6 |
| 6-40 | Inch | Fine | 0.025 | 40 |
Coarse Threads
- Lower TPI (Threads Per Inch) and larger pitch
- Easier assembly with faster installation
- Greater resistance to cross-threading
- Ideal for general-purpose fastening, industrial machinery, and construction hardware
Fine Threads
- Higher TPI and smaller pitch
- Provides higher tensile strength and fatigue resistance
- Better for precision equipment, aerospace, automotive, and high-stress applications
- Excellent for vibration-resistant fastening
Why Stanley Alloys Coarse & Fine Thread Screws Are Trusted
- Wide Range of Sizes: Metric M3.5–M14 and Inch #6–9/16 available with coarse or fine threads.
- Premium Stainless Steel Grades: 304, 316, 316L, 410, 2205 Duplex, A193 B8M for corrosion resistance and mechanical strength.
- Custom Manufacturing: CNC machining, cold forming, and hot forging to produce exact thread profiles and lengths.
- International Standards Compliance: DIN, ISO, ASTM, ANSI, JIS, BS for global compatibility.
Applications Across Industries
- Automotive, aerospace, marine, electronics, construction, and industrial machinery
- Secure fastening, superior mechanical strength, and corrosion resistance
- Precision assemblies and high-stress equipment