In-house tensile testing has been practiced at Lawton Standard St. Paul for many years.
This process measures our iron-casting materials’ tensile strength, yield strength, and elongation. The material specifications define their engineering properties, and the testing ensures that those quality requirements are met.
(Not all iron foundries have internal tensile testing machines and rely on outside sources, which delays the results.)
Elemental analysis is performed on an optical emission spectrometer. This device has a short measuring time with exceptional precision and stability. It provides a radiation reading emitted from an arc spark that is collected and shown as a percent concentration. Each element reading emits a different wavelength of radiation (color) when transitioned through various energy states. By measuring these wavelengths, the concentration and presence of various elements is determined.
Nodularity testing for each tap is verified using a standard ASTM testing slug. Each slug is polished and viewed with 100X magnification in a light microscope. The percent nodularity is compared to an American Foundry Society (AFS) rating chart. Based on these established standards, iron castings are thereby certified as having passed specified customer required standards.
Lawton Standard St. Paul recognizes the importance of controlling mold sand because it affects material metallurgy and overall casting quality in several ways.
Sand controllers are used with our sand mixers to maintain sand within our process parameters. These controllers are located at mixers that mix and deliver the sand to the molding machines. The mixers measure and control each batch of sand mixed. Lawton Standard St. Paul’s laboratory also samples sand at each line and performs several lab tests, including compatibility, green compression strength, permeability, and methylene blue clay characteristics. Automatic controls and lab test data provide statistics, x-bar charting, trend graphs, and histograms for consistent analysis over time.
Lawton Standard St. Paul utilizes two ovens certified to AMS 2750E for annealing and stress-relieving iron castings.
When outside heat-treating iron castings is needed, all chemistries are specified and controlled by Lawton Standard St. Paul. These outside heat treatment operations can include: normalize and temper, quench and temper, austemper, and induction harden.
Under New Ownership
We are excited to announce that Northern Iron is now part of The Lawton Standard Co. and will be known as Lawton Standard St. Paul, MN.