Custom Metal Stamping for OEM Hardware

1. What Is Custom Metal Stamping?

Metal stamping is a cold-forming manufacturing process that uses dies and presses to transform flat sheet metal into finished parts through operations like blanking, piercing, bending, forming, drawing, and coining. It's one of the most cost-effective methods for producing hardware components at volume — once the die is built, each press stroke produces a finished or near-finished part in seconds.

In industrial hardware manufacturing, stamping produces the structural backbone of many products: mounting brackets, springs, cam mechanisms, strike plates, locking bars, hinge leaves, clips, and decorative trim. These parts are often combined with die-cast components in the final assembly — the stamped part provides spring properties, structural rigidity, or mounting interfaces that die casting cannot achieve.

At Hengchieh, our stamping department runs 14 presses ranging from 6.3T to 120T, handling sheet thickness from 0.1mm (precision springs) to 6mm (structural brackets). This range covers virtually all hardware stamping requirements.

2. Types of Metal Stamping Processes

Progressive Die Stamping

Progressive stamping feeds a continuous strip of metal through a die with multiple stations. Each station performs one operation — the first might blank the outer profile, the second pierces holes, the third bends a tab, and the fourth cuts the finished part from the strip. The strip advances automatically between press strokes, producing one finished part per cycle at rates of 30–200+ strokes per minute.

Progressive dies are ideal for complex parts that require multiple operations and high volumes (10,000+ units). The die itself is more expensive ($5,000–$15,000+) but per-unit production cost is extremely low due to automated operation and fast cycle times.

Compound Die Stamping

Compound dies perform multiple cutting operations (blanking and piercing) in a single stroke. The advantage is superior flatness — since cutting happens simultaneously from above and below, the part emerges flatter than progressive stamping. Compound dies are best for simple flat parts (washers, gaskets, mounting plates) that require tight flatness tolerances.

Single-Station Stamping

For lower volumes or simple operations (a single bend, a single pierce), single-station dies provide the lowest tooling cost ($500–$3,000). The operator manually feeds parts or blanks. Production rate is lower but tooling investment is minimal.

Deep Drawing

Deep drawing forms flat sheet metal into cup-shaped or box-shaped parts through a series of drawing operations. It's used for hardware components like cylindrical lock housings, cable glands, and cap covers. Drawing ratio (depth-to-diameter) and material ductility determine feasibility.

3. Materials for Stamped Hardware Components

Material selection directly affects tooling design, press tonnage requirements, and surface treatment options. Stainless steel, for example, requires 50–70% more press force than cold-rolled steel for the same bend, which means larger presses and heavier-duty tooling. Our 120T press handles the heaviest stainless steel and thick-gauge stamping, while our fleet of 6.3T–40T presses handles high-speed production of lighter-gauge components.

4. Design Guidelines for Stamped Parts

Minimum Bend Radius

The inside bend radius should be at least 1× the material thickness for ductile materials (cold-rolled steel, aluminum) and 2× for less ductile materials (stainless steel, spring steel). Tighter bends risk cracking on the outside of the bend. When the design requires a sharp bend, consider a pre-scoring operation or selecting a more ductile material grade.

Hole Size & Edge Distance

Minimum hole diameter should be at least 1× material thickness. Hole-to-edge distance should be at least 2× material thickness. Hole-to-hole spacing should be at least 2× material thickness. Violating these minimums causes die wear, burr formation, and part distortion around the punched features.

Bend Relief

When a bend line meets a cut edge, a bend relief (small cutout or slot at the intersection) prevents tearing. The relief should be at least 1× material thickness wide and extend at least 1mm beyond the bend line.

Grain Direction

Sheet metal has a grain direction from the rolling process. Bending perpendicular to the grain direction gives the best results and maximum strength. When parts have bends in multiple directions, orient the most critical bend perpendicular to the grain and position other bends at 45° angles.

Tolerances

Standard stamping tolerances: blanked dimensions ±0.1mm, formed dimensions ±0.2mm, bend angles ±0.5°. For tighter requirements, secondary CNC operations can bring critical features to ±0.02mm. Communicate your functional tolerances clearly — not every dimension needs tight control, and specifying unnecessarily tight tolerances increases cost.

5. Tooling & Cost Considerations

The break-even point for progressive die tooling versus CNC or laser cutting is typically around 3,000–5,000 units. Below that volume, tooling-free methods are more economical. Above it, the per-unit cost advantage of stamping grows rapidly with volume.

6. Stamping + Die Casting: The Integrated Approach

Most industrial hardware products combine stamped and die-cast components. Understanding how these processes complement each other is key to designing cost-effective, high-performance hardware.

Die Casting Strengths

Complex 3D geometry, integrated features (bosses, ribs, channels), excellent surface finish for visible parts, tight tolerances on as-cast features, and net-shape or near-net-shape production that minimizes material waste.

Stamping Strengths

Spring properties (die castings are brittle and cannot spring), thin cross-sections (0.1–2mm), flat profiles with bent features, lower tooling cost for simple geometries, wider material choice (spring steel, stainless, copper), and extremely fast cycle times at high volume.

Combined Example: Industrial Lock Assembly

A typical industrial cam lock contains 8–12 components, combining both processes: the lock body is zinc die-cast (complex 3D form, smooth exterior surface), the cam blade is stamped steel (needs spring-back resistance and thin profile), the cylinder core and key pins are CNC-machined brass (precision bore tolerances), the clip ring is stamped spring steel (elastic retention force), and thedecorative cap may be injection-molded plastic (color-matched, branding).

When one manufacturer handles all these processes, dimensional compatibility is guaranteed, assembly is optimized, and the customer receives a single finished-goods SKU rather than managing multiple component suppliers. This is exactly how Hengchieh produces our full range of cam locks,panel locks, andswing handle locks.

7. Applications in Industrial Hardware

Structural Brackets & Mounting Plates

Stamped steel and stainless steel brackets are the invisible workhorses of hardware assemblies. They mount locks to panels, reinforce hinge connections, and provide structural support for handle mechanisms. Material choice (cold-rolled for indoor, stainless or galvanized for outdoor) and thickness (1.2–3mm typical) depend on the load and environment.

Springs & Elastic Components

Lock springs, latch return mechanisms, detent springs, and clip fasteners require spring steel (65Mn, SK5) or stainless spring steel (SUS301). These parts must maintain their elastic properties over 50,000–500,000+ cycles. Proper heat treatment after stamping is critical for achieving the target spring rate and fatigue life.

Cam Blades & Locking Mechanisms

The cam (the rotating metal tongue that engages the strike plate) is typically stamped from 1.5–2mm cold-rolled or stainless steel. Precise bend angles determine the cam's throw distance and locking force. Variations include straight cams, offset cams, and hooked cams for compression action.

Hinge Components

Hinge leaves, pintles, and bearing surfaces for industrial hinges are stamped from steel or stainless steel sheet. Surface and concealed hinges for electrical enclosures need to meet specific opening angles (90°, 120°, 180°) and load ratings. Oursurface-mounted hinges andconcealed hinges catalogs show the range of geometries produced through stamping.

8. Frequently Asked Questions

What is the difference between progressive die and compound die stamping?

Progressive dies feed strip metal through multiple stations (blanking, piercing, bending) sequentially — ideal for complex parts at high volume. Compound dies cut multiple features simultaneously in one stroke — better for simple flat parts needing tight flatness. Progressive dies cost more but produce faster.

What materials can be metal stamped?

Cold-rolled steel, stainless steel (304, 316, 430), spring steel (65Mn, SK5), galvanized steel, copper, brass, aluminum, and phosphor bronze. Thickness range: 0.1mm to 6mm for most hardware applications.

What tolerances can metal stamping achieve?

Blanked dimensions: ±0.1mm. Formed features: ±0.2mm. Bend angles: ±0.5°. Precision fine-blanking: ±0.02mm. For tighter tolerances, secondary CNC machining can be applied to stamped parts.

What is the minimum order quantity?

Progressive die production: 2,000–10,000+ units. Prototype/low volume: 50–500 units via laser cutting or CNC punching (no tooling required). Break-even for stamping tooling is typically 3,000–5,000 units.

Can stamped parts be combined with die-cast parts?

Absolutely. Most industrial hardware combines die-cast bodies (complex 3D geometry) with stamped steel components (springs, brackets, cam blades). A vertically integrated manufacturer like Hengchieh handles both processes in-house, ensuring dimensional compatibility across processes. See our full capabilities.