O. K. Foundry Co., Inc., Since 1912

Gray and Ductile Iron Jobbing Foundry

Short run grey and ductile iron sand castings for industry

Ductile iron compressor housings.

OK Foundry makes short run gray and ductile iron sand castings from 1 lb. to 400 lbs. for all general industrial segments. With flexible no bake molding for heavier castings and manual jolt squeeze molding for lighter castings, OK Foundry can make most industrial iron castings in typical grades of gray and ductile iron. No bake cope and drag molding and manual jolt squeeze molding are compatible with most legacy tooling types including automatic molding tooling. With minimal reversible rigging, almost any tooling can be setup for efficient production of short run and lower volume iron castings on our molding lines.

Phenolic Urethane No-Bake (PUNB) Binder for Molding Flexibility

To support the widest range of casting sizes, shapes, and configurations, OK Foundry utilizes phenolic urethane binders for cope and drag molding and legacy match plate molding of heavier iron castings. Phenolic Urethane No-Bake binders (PUNB) create the strongest molds and cores. Castings with difficult solidification defects can often be cured by using hard molds made with PUNB binders to limit mold expansion during solidification. Cores made with PUNB binders have superior hot strength and PUNB cores in cold boxes can be reinforced with steel rods to solve problems with in mold heat stress breakage and bending of cores. Although urethane binders are expensive compared to other sand systems for higher volume production, they support the lowest cost production of difficult, legacy, prototype, or very short runs of industrial castings by reducing costs of tooling and preventing many mold hardness and assembly defects.

Economic order quantities for 50 lb. castings in No Bake molds start as low as 25 to 50 castings. Heavier castings are economically made with as few as 5, 10, or 15 castings per order.

No Bake Molds for Lower Cost 3D Printed Molds and Cores

3D printed cores mother mold design.

The best way to reduce the cost of 3D printed sand molds and cores for serial production is to limit the amount of sand that needs to be printed. By using No Bake mother molds to capture assemblies of complex 3D printed core packages or 3D printed casting geometry, the volume of sand that needs to be printed can be minimized. OK Foundry has been designing hybrid molds using high volume mixer made urethane sand and 3D printed mold components since 2012. By working closely with the leading 3D printed sand companies like Hoosier Pattern Inc., OK Foundry has developed sophisticated collaborative design workflows to integrate 3D printed sand components and traditional patterns for the most economical combination of hard tooling, 3D printed sand cores, and production line cope and drag molding for short run castings.

Hybrid molds of 3D printed cores and No Bake molds can lower costs for serial production of patternless iron castings.

Manual Jolt Squeeze Molding for Short Runs of Light Castings

Snap flask cam.

Manual jolt squeeze molding, a process we’ve used at OK Foundry for over 80 years, is still the least expensive process for short runs of light castings, about 15 lbs. or less. Even modern patterns from automatic machines like the Hunter HMP-10 and HLM-10, can be molded on a jolt squeeze machine with a 14 x 19 flask for ramp-up or ramp-down production of light castings that have been setup for automatic molding.

Economic Order Quantities for Short Run Castings

The number of molds made in one day is a good rough estimate for a minimum economic order quantity of molds. For example our no bake cope and drag line can make about 50 molds per day, so a minimum order for castings of a single impression mold might be 50 castings to avoid any extra costs for setups. A jolt squeezer molder can also make about 50 molds per day. The number of pattern impressions, number and type of cores, and the weight of castings also influence the economic order quantity of castings, so this is just a very rough guide to minimum economic order quantities.


Engineering Castings

OK Foundry supplies gray and ductile iron sand castings to makers of general industrial equipment from 1 to 500 lbs. in size and a wide range of applications.  With a complete pattern shop and 3D CAD design capabilities OK Foundry can develop a sand cast solution for most applications in gray or ductile iron.

Explore Engineering Castings

Architectural Castings

Architectural iron castings from OK Foundry are used in diverse applications ranging from structural ductile iron castings for DOT projects to accurate reproductions of historical castings on landmark buildings.  Using traditional pattern and mold making techniques or advanced digital reproduction, new designs and historic cast iron can be reproduced or restored accurately.

Explore Architectural Castings

Metal Types Poured

  • ASTM A48 Gray Iron Class 20, 25, 30, 35, 40
  • ASTM A546 Ductile Iron Grade 60-40-18, 65-45-12, 80-55-06
  • Aluminum A356.0
  • Silicon Bronze C87300

No Bake Molding

A resin bonded sand molding process (No Bake) is used to mold large, heavy, or complicated castings. Our resin bonded molding line is easy to tool for flexible casting of large short run castings.

Green Sand Squeezer Molding

Green sand squeezer molding is used to make smaller castings with a finer finish. Our manual green sand squeezers economically produce small castings in quantities of 10 to 1,000 pieces.

Historic Restoration

Almost any iron casting can be reproduced by our skilled pattern makers and foundrymen. O.K. Foundry has provided accurate reproductions of historical castings for some of the largest restoration projects.

Check out our Project Gallery to see some examples of reproduction iron castings.