HSM Engineering Ltd was recently asked to find a solution for metal material components where the stock material wasn’t available. With the ability to cut most material types via its extensive range of lasers and waterjet machines, HSM has now added to its capability double-sided lapping thicknesses to very tight tolerances.

Double-sided lapping is an ultra-precision manufacturing process

It is usually adopted for fabricating wafers, thin substrates, metal slice parts, etc. By this way, high flatness, parallelism, and surface integrity can be obtained on hard and brittle materials such as silicones, glass, and metals.

The double-sided lapping setup includes an upper lapping plate (always floating rather than rigid coupling), a lower lapping plate, sun wheel and gear ring. By placing the parts in a carrier and using rotation and pressure the material can be reduced. The universal wheels revolve around the sun wheel and the slurry is dropped from the holes on the upper plate while processing. As a result, both surfaces can be lapped at the same time, so the two surfaces are similar on profile, residual stress, surface roughness and subsurface defects.

Double-sided lapping with the relocatable upper plate is different from double-sided grinding with stationary upper plate which the parallelism of workpiece depends on the machine accuracy. Compared with the single-sided lapping, both surfaces are machined at the same time with similar removal mechanism and the efficiency doubles by double-sided lapping. In addition, the clamping stress is avoided, and machining stress induced on both surfaces are similar which will cause less deformation during the lapping process.

HSM have been providing solutions for many different components such as gaskets, seals, spacers, and piston rings using these methods. With our extensive approvals we can provide solutions to an array of sectors from Aerospace, Commercial, Energy, Medical and Nuclear.

H S M Engineering Ltd