Mold, Tool and Die Finishing

At Bales, we tackle common and complex surface finishing challenges with innovative solutions. Our engineers pay attention to every detail of your project — whether preparing the mold of a highly visible injection molded part or readying your tool or die for release, abrasion, or corrosion applications. No matter the desired finish, you’ll receive a quality job that meets SPE-SPI Standards and achieves optimal mold performance and product functionality.

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DIAMOND #3 Diamond Buff A1 0-1
#6 Diamond Buff A2 1-2
#15 Diamond Buff A3 2-3
PAPER 600 Grit B1 2-3
400 Grit B2 4-5
320 Grit B3 9-10
STONE 600 Stone C1 10-12
400 Stone C2 25-28
320 Stone C3 38-42
DRY BLASTED #11 Glass Bead D1 10-12
240 Aluminum Oxide Blast D2 26-32
#24 Aluminum Oxide Blast D3 190-230


This is where we make you shine, to whatever degree you desire.

Accurate mold polishing requires a partner with the knowledge of what questions must be asked and the skill to match your desired specifications. When working with Bales, you tap into four decades of mold polishing experience, resulting in a uniform surface finish to optimize your part performance.

Selecting the best surface finish is key to solving common manufacturing issues, including:

  • Part sticking - the right finish will enable easier release from the mold

  • Part retention - blast finishes can be used in lieu of undercuts and mechanical detents to aid in part retention when required

  • Imperfections and inconsistencies - mold polishing can create a uniform finish that removes tool and machining marks and hides imperfections



Diamond polishing results in the finest finish on molds and components to produce highly visible or lens quality parts. The SPI* A-2 is the most widely used diamond finish, providing good release and good visual parts. An SPI A-3 is a fine choice for release where a high-gloss appearance is not required. All diamond finishes work well with chrome and nickel coatings. 

*SPI® is a registered trademark of Plastics Industry Association (PLASTICS)

Next to diamond polishing, paper finishes are the second most refined finishes available. Paper finishes can produce a slightly reflective or glossy shine and very good release. They are often recommended for products that do not require a decorative or visual impact.

The most economical finish, stone finishes are also the first step in the process of paper and diamond polishing. Stone finishes provide good release, but deliver very little gloss to the plastic part. This is a good choice for strictly functional molded parts where aesthetics are of no importance.

When done properly, blasted finishes can produce some of the most interesting stipples and textures on mold surfaces. From a fine satin texture with varied degrees of gloss to a flat, no-gloss coarse stipple, Bales has the blast media to produce the proper finish for you. Blast finishes are also an excellent way to camouflage weld repairs and slight imperfections.


In order to achieve a quality finish, you must start with a clean foundation. Blasting is effectively used to camouflage weld areas, cleaning, and prepping parts for processing or to achieve a desired surface finish. Our blasting process works on a variety of shapes, sizes and materials due to controlled velocity, pressure and location as specific areas can be appropriately masked.

At Bales, we use the following abrasive media for our blasting services:

  • Glass beads

  • Aluminum oxide


This process uses various abrasive media to prepare and enhance surfaces for a variety of finishes and coatings.

Tumble blasting is used to process high quantities of small parts at the same time while remaining cost effective.

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