Mold Manufacturing

Burhoe Machine Works, Mold Division,specializes in thermoset molds, including liquid silicone injection, gum stock injection, and rubber injection and transfer.

We are a full-service mold manufacturer, serving molders throughout the United States with high quality injection molds.  Many of the molds we make are for parts used in medical, aerospace, and silicon wafer industries.  We concentrate in the development of specialized molds for customers with unique needs.  Because we work with silicone, rubber, and plastic and in multiple industries, we are sensitive to how each molder’s needs differ.

Every mold is designed with the latest in computer-aided drafting.  Solidworks software allows us to provide accurate runner system and part volumes to the customer before the mold is made.  Customers can view the 3D tool operating on a computer screen, just as it would in real life.

Liquid Injection Mold Making

Liquid Injection Molds

Liquid Injection Molds may look similar to molds for other products, but they are very different.  Extremely tight tolerances are required to keep these molds from flashing.  The elasticity of the material allows freedom to mold complex undercuts, permitting generous creative leeway in the part design.  Geometry that cannot be considered in plastic molding is normal in Liquid Silicone.  One of the areas in which we excel is the manufacturing of Liquid Silicone Molds.

Rubber Mold Making - Burhoe Machine Works Sonora California

Rubber Molds

Rubber molding is seen by many molders as an aged field, and as such they deliver similar tools as have been in use for decades.  We take a different approach at Burhoe Machine.  Our rubber molds feature 4140 material as a bare minimum.  Transfer molds feature solid bronze pistons for long life, low material leakage, and ease of use.  Due to our reliance on computerized machinery, our lead times for rubber molds are often half that of the competition.  It is not uncommon for Burhoe Machine Works to expedite a mold for a 2-week delivery.

Polished Mold Making - Burhoe Machine Works

Polished Molds

Burhoe Machine Works is an excellent source for highly polished molds.  Only the best Electro-Slag Remelt and Vacuum Degassed steels are used to produce water-clear parts. This ensures that the steel can be brought up to a high luster (SPI-A1 spec).  It also ensures that when the 100,000th part comes out of your mold it looks the same as when the first article was molded. Steels that do not have the proper cleanliness will “dull out” over time.  To get the best polish, and to keep that polish for years, one needs to focus on cleanliness when the steel is poured.

As a side note, we use ESR steels on all molds when the customer demands longevity in high-stressed applications.  Inter-granular corrosion, fatigue cracking, and heat checking typically begin at the point of a microscopic inclusion in the metal.  Ensuring that the alloy is clean and heat treated to exacting standards is the only way to guarantee the correct, uninterrupted crystalline structure in the steel. 

Plastic Injection Mold Making -

Plastic Molds

Due to demand for less expensive consumer products, molding and mold making for plastic parts has recently seen a shift to overseas production.  Burhoe Machine Works employs high quality, competitive pricing, and quick lead times to keep the business here.  Our strategies are working.  Since our inception, we have had growth in plastics molds every year.  Take a look below to see why!