Tonkawa Lowers Raw Material Costs with Charge Calculator

Metalcasters can make several adjustments to their operations to reduce their costs, from making their energy use more efficient, to reducing labor costs by automating. Reducing the cost of raw materials, which amounts to a majority of casting cost, also can make a significant difference to the bottom line.

Tonkawa Foundry Inc., Tonkawa, Okla., a 30-employee, nobake and coldbox iron shop, found a way to save hundreds on a single heat using the Least Cost Charge Calculation program from MWK Software. The calculator uses linear programming to determine the least expensive recipe to charge a furnace to a given chemistry. It considers the cost, chemistry and availability of a metalcaster’s melt stocks in the calculations, which can be tailored to reflect melt losses from contamination, paint, oil and rust, as well as element by element losses while melting.

For Tonkawa, which uses a pair of 1,000-lb. furnaces to heat between 6 and 10 batches per shift, the software paid for itself in a couple of heats.

“What took me half a day now takes 10-15 minutes with this program,” said Jim Salisbury, COO and co-owner of Tonkawa Foundry.

The software program includes four main parts: final additions, least cost charge calculations, melt stock costing and calculating campaigns of charges.

Salisbury makes the most use out of the heart of the program, the Least Cost Charge Calculation, which allows users to select as many melt stocks as needed to find the least expensive charge recipe. The program calculates lower cost charges than its human counterpart because it is able to consider more details, chemistries, costs and availabilities.

If Salisbury needs to purchase stainless steel, his supplier will send him a list of different stainless steel alloys with their prices. Salisbury can then input the information into the Least Cost Charge Calculation program to determine what the most cost-effective scrap will be.

Tonkawa also makes use of the ability of the software to integrate with spectrometer software. This allows Salisbury to quickly adjust the chemistry and cost calculations if he needs to change a charge.

“I’m able to recalculate my charges in a snap,” Salisbury said.

The Least Cost Charge Calculation program can find the most cost-effective charge recipe in a matter of seconds. Users can restrict the use of melt stocks to meet volume restrictions, melting considerations or air filtration limits.