Two Ways to Make a Clipper Blade
There are two fundamentally different approaches to manufacturing clipper blades: traditional machining and MIM (Metal Injection Molding) powder metallurgy. Understanding the difference explains why some blades are more consistent, more durable, and more precise than others.
Traditional Machining: The Old Way
Traditional clipper blade manufacturing starts with flat steel stock (typically 440C stainless steel) and removes material through a series of cutting, stamping, and grinding operations until the blade reaches its final shape.
A typical traditionally-machined blade goes through 30-42 separate operations: blanking, punching, rough grinding, heat treatment, fine grinding, lapping, deburring, surface finishing, and more. Each operation introduces potential for variation, and maintaining tight tolerances across 30+ steps requires careful process control.
Traditional machining works well for simple blade geometries (flat blades with straight teeth), but struggles with complex shapes, deep channels, and intricate tooth patterns.
MIM Powder Metallurgy: The Modern Method
MIM (Metal Injection Molding) is a fundamentally different approach. Instead of removing material from a solid block, MIM builds the blade from metal powder — achieving complex shapes in a single forming step that would require dozens of machining operations.
The MIM process in ~20 steps:
Stage 1: Feedstock Preparation
Fine metal powder (typically 17-4PH stainless steel or 440C, particle size 5-20 microns) is mixed with a polymer binder to create a "feedstock" — a material that flows like plastic but contains over 60% metal by volume.
Stage 2: Injection Molding
The feedstock is heated and injected into a precision mold under high pressure — exactly like plastic injection molding. The mold can produce multiple blades per shot (multi-cavity tooling), and the near-net-shape forming means the blade comes out of the mold already in its final shape, including teeth, mounting holes, and channels.
This is where MIM's advantage is clearest: geometries that would require 15-20 machining operations can be formed in a single injection cycle.
Stage 3: Debinding
The molded "green part" contains approximately 40% polymer binder by volume. Debinding removes this binder through a combination of solvent extraction and thermal processing. The result is a fragile "brown part" — a metal skeleton with approximately 40% porosity.
Stage 4: Sintering
The brown part is placed in a high-temperature furnace (1,000-1,400°C depending on the alloy) under controlled atmosphere. During sintering, the metal particles fuse together and the part shrinks by approximately 15-20% in all dimensions, reaching near-full density (96-99% theoretical density).
The sintered part has mechanical properties comparable to wrought metal — similar hardness, tensile strength, and wear resistance.
Stage 5: Finishing
After sintering, the blade undergoes final operations: precision grinding of cutting edges, surface finishing (polishing, plating, or coating), and quality inspection.
Why MIM Produces Better Clipper Blades
Consistency: Every blade from a MIM mold is dimensionally identical. Traditional machining introduces variation at each of 30+ steps; MIM achieves final geometry in one forming step.
Complex geometries: MIM can produce blade shapes impossible with traditional machining — deep channels, undercuts, complex tooth patterns, and thin-wall sections. This is especially important for A5 detachable blades and guard comb blades, where precise tooth spacing directly affects cutting performance.
Material properties: Sintered MIM parts achieve 96-99% theoretical density — comparable to wrought metal. The fine, uniform microstructure of sintered metal often provides better wear resistance than conventionally machined parts.
Efficiency: MIM requires approximately 20 process steps versus 30-42 for traditional machining — a 40-50% reduction in manufacturing complexity. Less complexity means lower cost at scale and fewer opportunities for defects.
SUMTHIN's MIM Manufacturing
SUMTHIN operates its own MIM production line with dedicated powder metallurgy workshop. Our MIM capabilities include:
Products manufactured using MIM at SUMTHIN include:
Beyond Blades: MIM for Custom Parts
MIM isn't limited to clipper blades. The same technology can produce any small, complex metal part — gears, brackets, medical instruments, firearm components, watch parts, and automotive components.
If you have a metal part that currently requires multiple machining operations, MIM may offer a more consistent, cost-effective alternative. SUMTHIN has independent mold design capability and can evaluate your part for MIM feasibility. Contact us with your drawings or samples for a free assessment.