Pad Printing: Process, Design, Quality, and Cost

Pad printing is an indirect offset gravure process that uses a flexible silicone pad to transfer a 2D ink image from an etched plate onto a 3D object. It is ideal for printing on curved, textured, or recessed surfaces where flat screen printing cannot reach.

To properly sand stainless steel, start with a 36 to 60-grit abrasive for weld removal or deep scratches. Progress sequentially through 120, 240, and 400-grit to refine the surface. Always sand parallel to the grain and strictly use iron-free (INOX) abrasives to prevent corrosion.

Spray coating for metal parts applies liquid paint or powder to enhance corrosion resistance and aesthetics. However, engineers must account for coating thickness—typically adding 20 to 100μm per surface—requiring strict DFM planning for masking, threads, and mating surfaces to prevent assembly interference.

A satin metal finish is a smooth, low-gloss surface created through controlled abrasive machining. Its microscopic texture diffuses light to reduce glare and hide minor fingerprints and scratches. Unlike a bright mirror polish, it provides a uniform, muted sheen ideal for visible cosmetic components.

A mirror finish, often classified as a No. 8 finish, is a highly reflective, scratch-free surface achieved through progressive mechanical grinding and buffing. For industrial metal parts, it typically requires a surface roughness (Ra) below 0.1 μm to produce a clear, distortion-free reflection.

Electropolishing is an electrochemical finishing process that removes a thin, controlled layer of metal from a part’s surface. Often called reverse electroplating, it selectively dissolves microscopic high points to reduce surface roughness, remove micro-burrs, and improve corrosion resistance on alloys like stainless steel.

Metal phosphating is a chemical conversion process that treats steel and iron with a dilute phosphoric acid solution. It creates a bonded crystalline layer that prevents corrosion, reduces friction, and acts as an optimal primer for paint, powder coating, and rust-preventative oils.

To successfully grind stainless steel, operators must control heat to prevent warping and discoloration. Use INOX-rated ceramic or zirconia abrasives, apply consistent light pressure, and keep the grinder moving. Never use carbon steel tools on stainless steel to avoid iron contamination and rust.

The main difference between brushed and polished stainless steel is surface texture. Brushed stainless steel features a matte, directional grain that hides scratches and fingerprints. Polished stainless steel offers a smooth, highly reflective mirror-like surface with superior cleanability.

Deburring is a secondary manufacturing process used to remove burrs, sharp edges, and loose material fragments left on a workpiece after machining or cutting operations. It ensures part safety, tight tolerances, and proper assembly fit.

Aluminum chromating (also known as chem film or Alodine) is a chemical conversion process that creates a thin protective layer on aluminum. It provides excellent corrosion resistance, maintains surface electrical conductivity, and serves as an ideal base for paint, without altering part dimensions.

To polish stainless steel, clean the surface thoroughly, then use progressive abrasives starting from the grit that matches your deepest defect (e.g., 80-grit). Refine scratches sequentially up to 1200-grit, and finish by buffing with cutting and coloring compounds to achieve the desired brushed, satin, or mirror finish.