Grade 420 stainless steel is a high-carbon martensitic stainless steel designed to deliver exceptional hardness, high strength, and moderate corrosion resistance. Often referred to as “surgical steel,” this alloy can be heat-treated to achieve a rockwell hardness of up to 50 HRC, making it the premier choice for cutting edges, wear surfaces, and high-stress mechanical parts.
💡 Key Characteristics & Properties
High Wear Resistance: Thanks to its high carbon content, Grade 420 can be hardened through quenching and tempering to resist severe abrasive wear.
Moderate Corrosion Resistance: It offers good resistance to fresh water, mild acids, alkalis, air, and food acids, but only when it is fully hardened and polished.
Magnetic Nature: Unlike austenitic grades (like 304 or 316), Grade 420 is highly magnetic in all conditions.
Limited Weldability: Due to its hardening characteristics, welding Grade 420 is difficult and requires extensive pre-heating and post-weld annealing to prevent cracking
🛠️ Common Applications
Grade 420 is widely used in industries requiring sharp edges, high tensile strength, and hygienic properties:
Cutlery and Blades: Chef knives, hunting knives, and industrial shear blades that must hold a sharp edge.
Medical Instruments: Surgical tools, dental instruments, and forceps due to their hardness and ability to withstand repeated sterilization.
Mechanical Components: Valve parts, pump shafts, needle valves, pistons, and ball bearings subjected to continuous friction.
Plastic Moulds: Injection moulds that require high polishability and resistance to abrasive plastics.
Our External and Internal Circlips are available in 420 Stainless, and available to order online.
Preload disc springs are specialized, conically-shaped washers designed to apply a continuous axial force to bearings and mechanical assemblies. By maintaining constant tension, these components take up internal clearance, eliminate play, and significantly reduce noise and vibration.
Here is everything you need to know about how preload disc springs optimize mechanical systems.
💡 Why Bearing Preload Matters
In rotating machinery, ball bearings require a specific amount of tension to operate efficiently. Without proper preloading, ball bearings experience several mechanical issues:
Mismatched Rotation: Balls slide or skid instead of rolling properly, causing rapid wear.
Axial Play: Unwanted movement along the shaft damages precision.
Resonance: Excessive vibration shortens the lifespan of surrounding components.
Preload disc springs solve this by maintaining a constant, predictable load that keeps the rolling elements firmly seated in their raceways.
⚙️ Key Technical Benefits
Compensates for Thermal Expansion: As operating temperatures rise, shafts expand. Disc springs flex to absorb this dimensional change without overloading the bearing.
High Force in Compact Spaces: Unlike standard coil springs, disc springs generate massive axial force while occupying minimal linear space.
Configurable Performance: You can stack disc springs in different arrangements to modify performance:
In Series (Opposing directions): Increases total deflection (travel) while keeping the force the same as a single spring.
In Parallel (Same direction): Increases total force while keeping deflection the same as a single spring.
🛠️ Common Industrial Applications
Preload disc springs are essential components across high-precision and heavy-duty industries:
Electric Motors: Minimizes rotor shaft float and reduces operational noise.
Machine Tool Spindles: Ensures extreme axial rigidity for precise cutting and milling.
Automotive Drivetrains: Maintains clutch and transmission alignment under variable loads.
Pumps and Compressors: Absorbs axial thrust forces generated by high-velocity fluids.
Few hardware components achieve the status of a generic trademark, but the Terry Clip (Tool Clip) stands alongside items like the Hoover or the Allen key. Celebrated for its simplicity and mechanical efficiency, this modest clip remains an essential fixture in residential garages, commercial workshops, and heavy manufacturing.
__ __ <- Flexible Spring Arms
/ \___/ \
| | <- Grips Cylindrical Objects
| O | <- (Tool handle or pipe)
\ ___ /
|_| |_|
| O | <- Mounting base with screw hole
+-----+
The History: From Redditch to the World
The story of the Terry clip begins in Redditch, Worcestershire, England in 1855. originally manufactured wire hooks and springs, pulling from the region’s established expertise in handling steel wire for needle making.
By the early 20th century, the rise of the safety bicycle created a unique problem: cyclists needed a reliable way to carry handheld tire pumps without them rattling loose or falling into the spokes. Herbert Terry & Sons answered this by stamping high-tensile spring steel into a custom “C” or “U” shape profile. The fastener grabbed the pump tightly using raw kinetic tension, yet allowed the rider to instantly yank it free in an emergency.
As the decades progressed, the company expanded this fundamental design concept into automotive accessories, exercise gear, bicycle saddles, and the globally famous Anglepoise lamp.
Mechanical Design and Material Science
The high utility of a classic Terry clip stems directly from its engineering:
Spring Steel Architecture: True industrial Terry clips are manufactured using high-carbon spring steel or manganese steel. This material allows the arms of the clip to repeatedly flex wide open when an object is pushed inside and immediately snap back tightly to its resting parameter without losing its structural memory or clamping force.
Surface Treatments: Because carbon steel is vulnerable to oxidation, manufacturers apply protective finishes. The most common configuration is Bright Zinc Plating (BZP), which offers robust rust defense for garage environments. For premium marine or medical deployments, solid stainless steel is utilized.
Protective Coatings: Modern variations often feature a spring-steel core treated with an exterior skin of polyvinyl chloride (PVC), nylon, or rubberized coatings. These protective layers increase frictional grip while preventing the metal from scratching delicate surfaces, such as polished copper piping or carbon fiber shafts.
Key Variations: Open vs. Closed Type
While the mechanics are identical, Terry clips are categorized into two primary form factors:
Closed-type clips feature extended metal bands at the anchor point that loop entirely around to create a completely enclosed circular boundary at the bottom. This design distributes heavy physical loads across a wider surface area. They are the default pick for mounting heavier items vertically, like industrial breaker bars or heavy sledgehammers.
Open-type variants use a streamlined, narrow mounting profile where the spring arms stem directly up from a single central anchor screw. This compact footprint makes them ideal for tight spaces, small hand tools, or routing lines where horizontal real estate on the backing board is restricted.
Universal Applications
Thanks to their flexible design footprint—ranging from tiny 6mm diameters up to large 100mm variations—Terry clips are vital across multiple modern fields:
Workshop and Garage Organization: Keeping screwdrivers, chisels, torque wrenches, and brooms perfectly indexed on tool boards or shadow walls.
Plumbing and Infrastructure: Serving as durable wall hangers to secure copper or plastic conduit lines, while isolating the pipe from vibration and chafing.
Automotive and Transit: Holding emergency fire extinguishers, flashlights, or tools inside fleet trucks, off-road vehicles, and vintage car trunks.
Structural Framing: Serving as fast-assembly anchor joints for modular aluminum frames, such as temporary commercial gazebos or backyard trampoline enclosures.
Extractable dowel pins (also known as pull dowel pins) are specialized, precision-ground fasteners used to accurately align, position, and hold machine components together while allowing for easy removal from blind holes. Unlike standard dowel pins, which require an exit hole to be punched out from behind, extractable dowel pins feature an internal thread. This internal thread allows engineers to easily pull the pin out from the front using a matching screw or a specialized slide-hammer extraction tool.
How Extractable Dowel Pins Work
Standard dowel pins work beautifully in through-holes. However, when a dowel pin is pressed into a blind hole (a hole that does not go all the way through the material), removing it later becomes a destructive and frustrating nightmare.
Extractable dowel pins solve this specific issue through a simple design:
Internal Threading: The core of the pin is tapped with a standard metric or imperial internal thread.
Air Vent Flat: Most pull dowels feature a small ground flat side or an axial vent groove. This prevents air pressure from trapping the pin inside a blind hole during installation or removal.
Tapered Options: Some extractable dowels feature a slight taper, making them even easier to release from heavy-duty industrial machinery.
To extract the pin, a technician simply threads a bolt, threaded rod, or slide-hammer tool into the top of the pin and pulls it straight out without damaging the surrounding mating surfaces.
Key Benefits in Industrial Applications
Implementing extractable dowel pins over standard fasteners offers three primary advantages:
Effortless Maintenance: They completely eliminate the need for drilling out stuck pins, reducing machinery downtime from hours to seconds.
Component Protection: Because removal forces are applied inline via the thread, the surrounding precision-machined holes are protected from scratches, warping, or widening.
Infinite Reusability: Manufactured from hardened alloy steel or stainless steel, these pins can be inserted, extracted, and reused across hundreds of maintenance cycles
Technical Specifications to Consider
When sourcing extractable dowel pins for a project, pay close attention to these critical dimensions:
Nominal Diameter & Tolerance: Usually ground to precise tolerances (such as m6 or h6) to ensure an interference fit or tight clearance fit.
Thread Size: Standard sizing dictating the pull tool needed (e.g., an M6 diameter pin might feature an M3 or M4 internal thread).
Hardness Rating: Typically hardened to HRC 58-62 to ensure the extraction threads do not strip out under high pulling forces.
Starlock Washers are a highly efficient type of push-on fastener used to permanently grip smooth, unthreaded cylindrical shafts. Unlike standard washers that sit under a nut to distribute pressure, Starlock washers function as standalone retaining clips that bite deeply into a shaft to prevent components from working loose.
Here is a comprehensive breakdown of how they work, their key variations, and where they are most commonly used.
Starlock Washers feature a unique, angled internal tooth design that points inward.
Zero Threading Required: You can slide the washer down a plain metal, plastic, or composite axle without cutting any threads.
Instant, Permanent Lock: As the washer pushes onto the shaft, the inner teeth deflect outward. The moment any back-off force is applied, those sharp teeth bite aggressively into the shaft.
Vibration Resistant: They exert continuous initial tension, making them highly effective at preventing parts from rattling loose on moving machinery.
One-Way Assembly: Once secured, they are nearly impossible to slide back off without destroying the fastener.
Common Applications
Because they eliminate the time and cost of machining snap-ring grooves or threading shafts, you will find them everywhere in consumer and industrial assemblies:
Wheeled Goods: Safely retaining the wheels on the smooth metal axles of prams, pushchairs, toy cars, and hand trucks.
When you look at a piece of heavy machinery, a vehicle engine, or an industrial pump, your eyes are naturally drawn to the massive components: the spinning shafts, the heavy gears, and the roaring motors.
But deep inside those connection points lies a tiny, unassuming rectangular bar that keeps the entire system from spinning out of control.
It is called key steel. Without it, modern mechanical power transmission would grind to a halt. Here is everything you need to know about this critical engineering material.
What is Key Steel?
Key steel (often referred to as key stock) is a high-quality, precision-drawn steel bar used to manufacture mechanical keys. These keys are inserted into a matching slot—known as a keyway—cut into both a rotating machine shaft and the hub of a component (like a gear, pulley, or sprocket).
The key acts as a mechanical lock. It prevents relative rotation between the two parts, ensuring that when the shaft turns, the gear turns with it. If the machine experiences an extreme overload, the key is designed to fail or shear first, protecting much more expensive components from catastrophic damage.
Why the Right Material Matters
You cannot just cut a piece of scrap metal and use it as a machine key. Key steel is specifically engineered to meet strict dimensional and physical requirements.
Dimensional Precision: Key steel is manufactured to incredibly tight tolerances. Because it must fit perfectly into a keyway without slipping or jamming, it is typically drawn with a minus tolerance (meaning it is exactly the nominal size or a fraction of a millimetre smaller).
High Tensile Strength: It must withstand immense torsional (twisting) forces. Standard mild steel would twist or deform under heavy industrial loads, leading to loose components and machine failure.
Machinability: While tough, key steel must still be easy enough to cut, file, and fit by maintenance engineers working in the field or in a machine shop.
Wave spring washers are specialized, wavy-shaped fasteners designed to provide predictable radial and axial force within highly restricted spaces. Unlike traditional coil springs or bulky Belleville washers, wave washers optimize space by reducing operating heights by up to 50% while delivering identical force profiles. This makes them the industry standard for eliminating play, absorbing shock, and maintaining critical tension in modern precision engineering.
_..---.._ <-- Wavy, undulating profile
.-' '-. deflects under axial load
(_______________) to provide constant tension
Strategic Mechanical Advantages
Space-Saving Geometry: Operates in compact cavities where standard compression springs physically cannot fit.
Compensation for Wear: Automatically absorbs axial slack caused by thermal expansion, component wear, or manufacturing tolerances.
Precise Bearing Preload: Applies a smooth, continuous force to ball bearings, drastically reducing operating noise and preventing premature bearing failure.
Uniform Force Distribution: Offers 360-degree radial load distribution without the high stress-concentration points common in standard lock washers.
316 grade stainless steel is a premium austenitic alloy renowned for its superior corrosion resistance and exceptional durability. Often referred to as “marine grade” stainless steel, it is the second most common commercial grade after 304.
The Molybdenum Difference
The secret to the high performance of 316 lies in its chemical composition. While it contains standard chromium and nickel, it also incorporates 2% to 3% molybdenum. This crucial addition provides heavily upgraded protection against pitting, crevice corrosion, and industrial chemicals, especially in harsh chloride-heavy environments.
Depending on your project requirements, different sub-grades of 316 optimize for specific environments:
Grade
Key Feature
Best Used For
316
Standard carbon content (0.08% max)
High-strength structural parts
316L
Low carbon content (0.03% max)
Heavy welding without losing corrosion protection
316H
Elevated carbon content
High-temperature applications like pressure vessels
Practical Applications:
Marine Equipment: Boat fittings, coastal architectural fascia, and underwater infrastructure.
Chemical & Medical: Pharmaceutical equipment, specialized surgical devices, and processing plants.
Food & Beverage: Commercial kitchenware, dairy processing, and brewing systems due to its hygienic, easy-to-clean nature.
We welcome any enquiry you may have for 316 Stainless Steel Non-Threaded Fasteners.
In the oil and gas sector, component failure is not an option. Upstream drilling, midstream transport, and downstream processing equipment operate under some of the most hostile conditions on earth. Circlips—also known as retaining rings—play a critical role in these systems by securing bearings, shafts, and assemblies inside valves, pumps, and drilling tools.
When specifying retaining rings for oil and gas applications, standard carbon steel components are rarely sufficient. Engineers must account for extreme pressures, corrosive chemicals, and severe temperature fluctuations.
Key Technical Challenges
Corrosion Resistance: Components face constant exposure to sour gas (H₂S), carbon dioxide (CO₂), brine, and seawater. Standard materials suffer from rapid pitting and stress corrosion cracking.
High-Pressure, High-Temperature (HPHT): Downhole drilling tools operate at temperatures exceeding 200°C and pressures above 15,000 psi. Retaining rings must maintain their mechanical properties and gripping power without losing temper.
Hydrogen Embrittlement: High-strength steels exposed to corrosive environments can absorb hydrogen, leading to sudden, catastrophic brittle failure under tensile stress.
Material Selection Criteria
Material selection is the most critical factor for circlips in oil and gas applications. Standard rings are typically swapped for high-performance alloys:
Material Class
Common Alloys
Primary Benefit
Typical Application
Stainless Steel
316 Stainless, 17-7 PH
General corrosion resistance and excellent fatigue strength.
Surface pumps, valves, and marine topside equipment.
Nickel Alloys
Inconel X-750, Inconel 718
Exceptional strength at high temperatures; resists sour gas.
Downhole drilling tools, subsea valves, and completions.
Copper Alloys
Phosphor Bronze, Beryllium Copper
Non-magnetic and non-sparking properties; low friction.
Measurement-while-drilling (MWD) tools and explosive zones.
Here at Caleb Components, we are specialists in sourcing & supplying high quality Circlips in the above materials. Please contact us today with your enquiry.
Slotted spring pins—often called roll pins—are hollow, cylindrical fasteners with a longitudinal slot running down the entire length. They are engineered to be oversized relative to the hole they fit into, relying on self-retaining spring force to lock securely into place.
Key Functions and Engineering Benefits
Self-Locking Design: The pin compresses upon insertion and exerts continuous outward radial force against the hole wall, preventing loosening caused by heavy vibration or shock.
Cost-Efficient Production: They eliminate the need for high-precision reamed holes, as they easily accommodate wider hole tolerances than solid dowel pins.
Simplified Assembly: Standard chamfered ends create a smooth lead-in angle, allowing rapid installation using a basic hammer, punch, or automated pneumatic press.
Common Industrial Applications
Hinges and Pivots: Providing a low-wear, flexible pivot axis for moving mechanical linkages.
Gear and Shaft Anchoring: Securing gears, pulleys, or sprockets directly to rotating shafts to transmit light-to-medium torque.
Cross-Pinning Fasteners: Acting as a reliable safety lock to prevent larger nuts or components from backing off.
Our Slotted Spring Pins are available to purchase directly online.
