Fastener Set
PartWhat a fastener set is
Almost every assembly on BOMwiki ends, somewhere near its leaves, in a fastener set, the bolts, screws, nuts, washers and rivets that hold the real parts together. They are the most numerous components in manufactured goods (a car has thousands; an airliner, millions) yet the cheapest, often a fraction of a cent each. A fastener set is not one part number but a small kit chosen together so that thread, grade, length and coating all match the joint. This page explains how those choices are made; the linked catalogue pages list real, in-stock parts in every size.
The families below each have a faceted catalogue: Hex Head Bolts, Socket Head Cap Screws, Hex Nuts, Washers, Threaded Rod, Threaded Inserts and Blind Rivets.
Threads: the language of fasteners
A thread is defined by its diameter and pitch. Most of the world uses the ISO metric system, written M followed by the nominal diameter and, for fine threads, the pitch: M8 is 8 mm with the standard 1.25 mm coarse pitch, while M8x1 is the fine version. North America still uses the Unified system (UNC coarse, UNF fine), sized by a number or fractional inch and a threads-per-inch count, such as 1/4 inch-20. Coarse threads are faster to run down, more tolerant of damage and plating, and the default for general work; fine threads carry slightly more load, resist loosening a little better and suit thin-walled parts. The two are not interchangeable, and mixing them is a classic way to strip a thread.
Strength: property classes and grades
A fastener is only as good as the joint it can clamp, so steel fasteners are sold by strength, not just size. The metric system stamps a property class on the head: 8.8, 10.9 or 12.9 for high-strength work. The first number is roughly the tensile strength in units of 100 MPa (an 8.8 bolt is about 800 MPa), and the second encodes the yield-to-tensile ratio, so a 10.9 bolt yields at about 90% of its 1000 MPa tensile strength. The old US SAE grades 2, 5 and 8 are the rough equivalents of low-carbon, medium-carbon quenched-and-tempered, and alloy steel. Stainless fasteners are marked A2 (304-type) or A4 (316, with added molybdenum for marine and chemical use) followed by a strength such as -70 or -80; stainless trades some strength and galling resistance for corrosion resistance, so it is rarely run above A4-80.
Heads and drives
The head sets how the fastener bears on the surface and how much clamp area it has. A hex head is driven by a wrench from the side and dominates structural work; a socket (cap) head takes an Allen key from above and suits tight spaces and tapped holes; button and pan heads are low and rounded for light cosmetic work; a countersunk (flat) head sits flush in a chamfered hole. The drive is how torque gets in: internal hex/Allen and Torx (six-lobe) resist cam-out and allow high torque, while Phillips and slotted are cheap and self-centering but cam out under load.
Bolts vs. screws, and the rest of the kit
Strictly, a bolt passes through clearance holes and is tightened against a nut, while a screw threads into a tapped hole or the work itself, but usage is loose and the line blurs. The other members of the set each do one job. Nuts provide the mating thread: a plain hex nut for general use, a nylon-insert (Nyloc) or all-metal lock nut where vibration would otherwise back it off, a flange nut to spread load without a washer. Washers sit under the head or nut: a plain (flat) washer spreads load and protects the surface, a split-lock or tooth washer adds spring tension against loosening, a fender washer spans an oversized hole. Where a joint is permanent and accessed from one side, a blind (pop) rivet replaces the bolt-and-nut entirely, setting its own back-side head as the mandrel is pulled.
Materials, coatings and corrosion
Most fasteners are carbon or alloy steel, which rusts, so it is almost always coated. Zinc plating (clear or yellow) is the cheap default for indoor use; hot-dip galvanising lays on a thicker, rougher zinc layer for outdoor and structural steel; black oxide is a thin, mildly protective conversion coating favoured on socket screws and tooling; zinc-flake systems (Geomet, Delta-Protekt) give high salt-spray life without the hydrogen-embrittlement risk that electroplating poses to high-strength parts. Where coating is not enough, the fastener is made from stainless (A2/A4), brass for electrical and decorative work, or titanium and exotic alloys in aerospace.
Preload, torque and keeping it tight
A bolted joint works by preload, the tension stretched into the bolt as it is tightened, which clamps the parts and is what actually carries the load. Assemblers usually set preload indirectly with a torque wrench, relying on a nut factor (the "K" value, about 0.2 for plain zinc) to relate torque to tension; the relationship is approximate because most of the torque is lost to friction under the head and in the threads. Critical joints instead measure angle (turn-of-nut) or bolt stretch directly. Once tight, vibration is the enemy: it is resisted by thread-locking adhesive (anaerobic compounds such as Loctite), by prevailing-torque lock nuts, by tooth or wedge-lock washers, or simply by enough preload that the joint never loosens. Under-tightening, not over-tightening, is the more common cause of failure.
3D model
interactive · add or replaceLoads the viewer and a 564 KB model. Drag to rotate, scroll or pinch to zoom.
3D model: BOMwiki parametric · CC0 1.0 · Open in CAD player · Download STL (564 KB)
Where the fastener set is used
3,374 products across 52 domains contain it, directly or inside a sub-assembly- Machine Tools & Metalworking 198 CNC Milling Machine, Abrasive Chop Saw, Abrasive Flow Machining Machine, Angle Roll Bender, Metal Cutting Band Saw, Bed-Type Milling Machine, Bevel Gear Generator, Billet Shearing Machine, and 190 more
- Machinery & Industrial 193 All-Electric Injection Molding Machine, Ampoule Filling-Sealing Machine, Glass Annealing Lehr, Twin-Wire Arc Spray, Auto Shredder Residue Separator, Dynamic Balancing Machine, Mechanical Bar Screen, Powder Coating Booth, and 185 more
- Food & Beverage Processing 170 Aseptic Filler, Automatic Filleting Machine, Automatic Espresso Tamper, Bagel Former, Scraped Cooking Kettle, Ice Cream Batch Freezer, Fermentation Tank, Bin Sweep Auger, and 162 more
- Construction & Earthmoving 135 Screening Plant, Articulated Dump Truck, Articulated Haul Truck, Asphalt Batch Plant, Asphalt Distributor Truck, Asphalt Drum Mix Plant, Asphalt Recycler, Bulldozer, and 127 more
- Building & Construction Products 109 Access Control Panel, Accordion Storm Shutter, Acoustic Banner Hoist, Air Dancer, Intrusion Alarm Panel, Arena Basketball System, Folding Attic Ladder, AAC Block Plant, and 101 more
- Marine 107 Airboat, AIS Transponder, Anchor Handling Tug, Anchor Windlass, Aquarium Acrylic Tunnel, Aquarium Wave Maker, Aviary Misting System, Bait Chopper, and 99 more
- Agriculture & Construction 100 Agricultural Spray Drone, Air Seeder and Cart, Anhydrous Ammonia Applicator, Articulated Tractor, Automatic Calf Feeder, Bale Accumulator, Bale Shredder Feeder, Bale Wrapper, and 92 more
- Material Handling 94 Order Picker, Walkie Stacker, Articulated Forklift, AS/RS Stacker Crane, Automated Guided Cart (AGV), Automated Mooring System, Bag Dump Station, Bag Palletizer, and 86 more
- Textiles & Apparel Machinery 90 Air-Jet Loom, Air-Jet Spinning Machine, Automatic Fabric Cutting Machine, Bartack Sewing Machine, Belt Loop Attaching Machine, Blindstitch Hemming Machine, Cotton Blowroom Line, Button Attaching Machine, and 82 more
- Small Kitchen Appliances 89 Air Fryer, Automatic Pan Stirrer, Blender, Bread Machine, Bread Maker, Burr Coffee Grinder, Capsule Coffee Machine, Chocolate Fondue Fountain, and 81 more
- Power & Energy 88 Air-Insulated Substation Bay, Bottom Ash Handling System, Automatic Transfer Switch, Automatic Voltage Regulator, Autotransformer, Battery Swap Station, Biogas Generator (CHP), Busbar Trunking System, and 80 more
- Imaging & Optics 86 Action Camera, Adaptive Optics System, Astro Camera, Electronic Autocollimator, Binoculars, Police Body Camera, Borescope Inspection Camera, Camera Jib Crane, and 78 more
- Medical Devices 82 Anesthesia Machine, Audiology Booth, Autopsy Table, Autorefractor, Bath Lift, Bladder Scanner, Blood Bank Refrigerator, Phlebotomy Chair, and 74 more
- Home Appliances 81 Air Conditioner, Aroma Diffuser, Automatic Pet Feeder, Beverage Center, Beverage Refrigerator, Bladeless Fan, Boot Dryer, Box Fan, and 73 more
- Rail & Transit 80 Airport Apron Bus, Articulated Bus, Auto-Rack Railcar, Autorack Wagon, Axle Counter System, Ballast Regulator, Railway Bogie, Catenary Maintenance Vehicle, and 72 more
- Audio & Video 78 USB Audio Interface, Teleprompter, AV Matrix Switcher, AV Receiver, Portable Boombox, Broadcast Audio Console, Broadcast Studio Camera, Broadcast Graphics Engine, and 70 more
- Consumer Electronics 77 Air Quality Monitor, Portable AM/FM Radio, Amateur Radio Transceiver, AR Glasses, Video Baby Monitor, Bluetooth Speaker, Bluetooth Tracker Tag, Bone Conduction Headphones, and 69 more
- Automobiles 75 Hydrogen Fuel Cell Car, Solar Car, All-Terrain Vehicle, Ambulance, Amphibious Car, Armored Cash-In-Transit Truck, Auto Rickshaw, Beverage Delivery Truck, and 67 more
- Toys, Games & Hobby 75 Aerial Silk Rig, Air Hockey Table, Alpine Coaster, Animatronic Toy, Arcade Basketball Machine, Arcade Cabinet, Automatic Card Shuffler, Batting Cage System, and 67 more
- Office & Retail Equipment 73 Automated Book Return, AV Lectern, Checkout Bagging Carousel, Banknote Banding Machine, Banknote Fitness Sorter, Barcode Scanner, Comb Binding Machine, Overhead Book Scanner, and 65 more
- Lab & Scientific Instruments 71 Analytical Balance, Superconductor Materials Lab, Antenna Analyzer, Arbitrary Waveform Generator, Atomic Absorption Spectrometer, Autoclave Sterilizer, Automatic Titrator, Laboratory Centrifuge, and 63 more
- Robotics & Automation 70 AGV Mobile Robot, Autonomous Warehouse Robot, Arc Welding Robot, Robotic Assembly Cell, Assistive Feeding Robot, Autonomous Mobile Robot (AMR), Bin Picking Cell, Bricklaying Robot, and 62 more
- Oil, Gas & Process 70 Amine Gas Sweetening Unit, Blowout Preventer Stack, Oilwell Cementing Unit, Centrifugal Gas Compressor, Choke Manifold, Wellhead Christmas Tree, Natural Gas City Gate Station, CO2 Injection Pump, and 62 more
- Printing & Packaging Machinery 69 Auger Powder Filling Machine, Automatic Labeling Machine, Button Maker, Paper Banding Machine, Banner Welder, Book Sewing Machine, Film Bundling Machine, Capping Machine, and 61 more
- Power & Hand Tools 51 Angle Grinder, Belt Sander, Bench Grinder, Bench Power Supply, Biscuit Joiner, Chainsaw, Circular Saw, Cordless Caulking Gun, and 43 more
- Mining & Quarrying 51 Apron Feeder, Ball Mill, Blast Hole Stemming Loader, Carbon Regeneration Kiln, Flotation Column, Continuous Miner, Drill Core Orientation Tool, Diamond Core Drill Rig, and 43 more
- Computing & Peripherals 50 All-in-One PC, Barcode Verifier, Refreshable Braille Display, Video Capture Card, Computer Mouse, Hardware Crypto Wallet, Desktop PC, Docking Station, and 42 more
- Pumps, Valves & Fluid 49 Air Compressor, Axial Flow Pump, Ball Valve, Basket Strainer, Boiler Feedwater Pump, Butterfly Valve, Canned Motor Pump, Centrifugal Compressor, and 41 more
- Renewable Energy 48 Solar Crop Dryer, Archimedes Screw Turbine, Battery Energy Storage System, Biogas Upgrading Unit, Biomass Pellet Boiler, Concentrated Solar Power Receiver, Floating Solar Platform, Floating Offshore Wind Turbine, and 40 more
- Defense & Security 46 Aircraft Carrier, Amphibious Assault Vehicle, Armored Personnel Carrier, Nuclear Attack Submarine, X-Ray Baggage Scanner, Ballistic Helmet, Ballistic Shield, EOD Robot, and 38 more
- Plumbing & Sanitary 46 Above-Ground Pool, Automatic Pool Cover, Reduced-Pressure Backflow Preventer, Electronic Bidet Seat, Water Booster Pump, Composting Toilet, Condensate Removal Pump, Drinking Fountain, and 38 more
- Networking & Telecom 46 5G CPE Router, DOCSIS Cable Modem, 5G Base Station, Cellular Signal Repeater, Carrier Core Router, Data Center Switch (Spine), DECT Base Station, DAS Headend, and 38 more
- Furniture & Durables 43 Adjustable Bed Base, Baby High Chair, Baby Walker, Barber Chair, Bunk Bed, Cantilever Patio Umbrella, Cinema Recliner Seating, Drafting Table, and 35 more
- Space Systems 43 Space Station Treadmill, Satellite Laser Communication Terminal, Communications Satellite, Crewed Space Capsule, CubeSat Power Module, CubeSat, Deployable Solar Array Wing, Spacecraft Docking Adapter, and 35 more
- Cleaning & Floorcare 43 Air Mover / Carpet Dryer, Artificial Turf Groomer, Automatic Air Freshener, Auto Towel Dispenser, Automatic Soap Dispenser, Backpack Vacuum, Carpet Blower/Dryer Stack, Carpet Cleaner, and 35 more
- Personal Care & Grooming 41 Barrel Sauna, Beard Trimmer, Cryolipolysis Machine, Curling Iron, Ear Piercing System, Electric Callus Remover, Electric Shaver, Electrolysis Machine, and 33 more
- Sports & Fitness 40 Adjustable Dumbbell, Adjustable Kettlebell, Adjustable Weight Bench, Anti-Gravity Treadmill, Air Assault Bike, Climbing Auto-Belay, Belt Squat Machine, Boxing Ring, and 32 more
- Garden & Outdoor Power 38 Brush Cutter, Compost Tumbler, Powered Earth Auger, Electric Fence Energizer, Electric Uncapping Machine, Electronic Hose Timer, Electronic Rodent Trap, Garden Tiller, and 30 more
- Outdoor & Camping Gear 37 Release Aid, Avalanche Probe, Avalanche Transceiver, Backpacking Stove, Baitcasting Reel, Bow Press, Bow Sight, Rechargeable Camp Lantern, and 29 more
- Two-Wheelers & Mobility 35 Electric Scooter, Adventure Motorcycle, Battery-Swap Electric Moped, Cafe Racer Motorcycle, Chopper Motorcycle, Cruiser Motorcycle, Dirt Bike, Dual-Sport Motorcycle, and 27 more
- Dental & Veterinary 35 Dental Air Polisher, Dental Amalgamator, Dental Apex Locator, Dental Autoclave (Class B), Dental Oil-Free Compressor, Dental Cone Beam CT, Dental Curing Light, Intraoral Camera, and 27 more
- Aerospace & Drones 34 Aircraft APU, Commercial Airliner, Non-Rigid Airship (Blimp), Bush Plane, Business Jet, Cargo Delivery Drone, Agricultural Aircraft, Ejection Seat, and 26 more
- Lighting & Electrical 34 Aviation Obstruction Light, Emergency Exit Light, Explosion-Proof Light Fixture, LED Floodlight, Theatrical Followspot, Canopy Light, LED Grow Light, Heliport Beacon, and 26 more
- Bicycles & Cycling 34 Bicycle Cargo Trailer, GPS Bike Computer, Bicycle Repair Stand, BMX Bike, Cargo Bicycle, Cargo E-Bike, Cargo Trike, Child Bike Seat, and 26 more
- HVAC & Plumbing 31 Air Curtain, Air Handling Unit, Air Purifier, Electric Baseboard Heater, Ceiling Cassette AC, Ceiling Fan, Centrifugal Chiller, Commercial Kitchen Hood, and 23 more
- Firefighting & Emergency 30 Aerial Firefighting Tanker, Emergency Eyewash Station, Fire Hose Reel, Fire Monitor (Water Cannon), Breathing Air Compressor, Confined Space Winch, Decontamination Shower System, Emergency Vehicle Light Bar, and 22 more
- Musical Instruments 28 Autoharp, Banjo, Bass Guitar, Carillon, Celesta, Digital Piano, Drum Kit, Guitar Multi-Effects Processor, and 20 more
- Vending, Kiosks & ATMs 26 Airport Check-In Kiosk, Automated Teller Machine, Book Vending Machine, Bill Change Machine, Coffee Vending Machine, Currency Exchange Kiosk, French Fry Vending Machine, Golf Ball Dispenser, and 18 more
- Watches & Timepieces 22 Analog Alarm Clock, Radio-Controlled Atomic Clock, Carriage Clock, Chess Clock, Cuckoo Clock, Digital Desk Clock, Dive Watch, Flip Clock, and 14 more
- Elevators & Escalators 20 Boat Lift, Car Elevator, Two-Post Car Parking Lift, Dumbwaiter, Escalator, Building Maintenance Unit (Facade Cradle), Freight Elevator, Industrial Goods Lift, and 12 more
- Automotive Service Equipment 9 ADAS Calibration System, Automotive Paint Booth, Car Wash Tunnel System, Four-Post Storage Lift, Frame Straightening Rack, IR Curing Lamp, Paint Thickness Gauge, Tire Tread Scanner, and 1 more
- Airport Ground Support 4 Airport Pushback Tractor, Belt Loader, Lavatory Service Truck, Passenger Boarding Stairs
Used in 7991 assemblies
Sourcing: possible vendors
Browse the supplier directory → Prices, MOQ, and lead times are algorithmic estimates, not quotes, and not claims about these companies. Company mappings are curated by keyword; est. price band $0.01–$2. How estimates work| Vendor | HQ | Specialty | MOQ | Lead time |
|---|---|---|---|---|
| sundram.com ↗ | Chennai, IN | Fasteners | 10,000 pcs | 3–5 wks |
| lpsindia.com ↗ | Rohtak, IN | Fasteners | 10,000 pcs | 3–5 wks |
| escort-fastener.com ↗ | Suzhou, CN | Fasteners | 10,000 pcs | 3–5 wks |
| tbfastener.com ↗ | Shanghai, CN | Fasteners | 10,000 pcs | 3–5 wks |
| sterlingtools.in ↗ | Faridabad, IN | Fasteners | 10,000 pcs | 3–5 wks |
972-word article