No Surprises: How to Create a Casting Contract For the Best Casting Outcome
Question: Who’s the first point-person at the foundry responsible for looking at the buyer’s contract?
Porfilio: The best practice is for a talented and experienced quality and technical specialist to conduct the contract review––someone who can verify the minutia of things like process parameters, special needs, detailed specifications, drawings and testing. It’s important to note that despite all the particulars, contract review has to be expedited. The sooner the customer’s PO moves through the review and scheduling system, the quicker parts will be poured, which ultimately increases on-time delivery.
Question: What does the foundry expect the customer’s contract to contain?
Porfilio: The foundry needs the following key information from the customer: Part/pattern number; order quantity; material and material specification; quality requirements; any supplementary requirements; drawing revision levels and requirements; special processes like heat treatment, welding considerations, pickling and painting; testing requirements; and delivery requirements. One more thing that won’t be printed anywhere but is very important to the outcome of the job: In order for the foundry to fulfill all the customer’s requirements accurately and on time, they need good relationships and communication with the customers’ buyers and technical engineers. It’s vital that these people are accessible to answer questions the foundry may have before any metal is poured.
Question: What is the foundry going to do if one piece of the contract package conflicts with another piece?
Porfilio: Generally, contract review is performed in this order:
• Purchase order
• Drawings or prints
This sequence also drives the foundry’s decision-making if one element doesn’t agree with another. If something in the drawing conflicts with the specifications, they should follow the specifications; if the specification doesn’t line up with the PO, they should follow the PO; and likewise, the contract takes precedence over the PO. But my No. 1 advice to the foundry if they spot a conflict in requirements is: Call the customer.
Question: What are the most common standard specifications given to foundries?
Porfilio: The number of possible casting specifications is nearly endless, but the most common that will show up on casting orders are ASTM, ASME, MIL and NAVSEA, ISO and EN, plus NACE, NORSOK and API.
1) ASTM (American Society of Testing and Materials). ASTM comprises a series of specs for materials, nondestructive testing, testing practices and protocols, processing, welding and more. It sets out requirements for chemical ranges and gives limits for disposition of mechanical properties; provides both pressure and non-pressure specifications for cast materials; details mandatory tests, heat treatments, welding conditions and other processes; and includes some pass-downs to other governing specifications (A703, A781, etc.) that have overarching requirements.
2) ASME (The American Society of Mechanical Engineers). This is a pressure vessel series of code standards for both ferrous and non-ferrous alloys, many of which are similar if not identical to ASTM. A key distinguishing factor is that ASME is a safety standard––if something goes wrong, people may be injured. Foundries should certify their welders and qualify their nondestructive testing personnel to meet the requirements of ASME Boiler and Pressure Vessel Code (B&PVC).
3) MIL and NAVSEA (Military and Naval Sea Systems Command). Every aspect of these specifications is designed to over-qualify materials so they meet the rigors of high-end use. Most specifications in these two standards cover the entire material expectation, whereas other standards tend to hone in on welding, general NDT or inspections of welds, for example. MIL and NAVSEA are always very detailed––in some cases more than 10 times more detailed than ASTM––and always require proper procedures and personnel qualifications.
4) ISO and EN (European Nation). These types of standards take the level of difficulty to a new level. The PED (Pressure Equipment Directive), a European version of the ASME B&PVC series of documents, is a safety-based standard for handling castings and components with working pressures in excess of 0.5 Bar (7.25 PSI). American grades can be produced as long as they’re “harmonized,” (on an approved list of materials), or if they’re placed on a properly formatted PMA (Particular Material Appraisal). The European state where the part will be used has final approval.
5) NACE, NORSOK and API. (National Association of Corrosion Engineers / Norwegian shelf’s competitive position / American Petroleum Institute). Complicated in the extreme, these specifications deal with corrosion-intensive and/or petroleum-based materials and testing protocols. They set conditions for heat treatment, corrosion testing, material strength, and hardness as well as NDT, depending on the customer’s exact specification.
Question: How specific should the customer be about their testing expectations?
Porfilio: Make sure that the test methods and acceptance criteria have been well defined in the purchasing documents. Somewhere in the order the customer should specify visual inspection as well as other nondestructive testing (NDT) to verify the integrity of a casting that could impact safety, financial loss or operational downtime. Besides visual testing, NDT includes radiographic testing, penetrant testing, mag particle testing and ultrasonic testing. When it comes to nondestructive testing, the foundry will not stray from the PO’s requirements, so they should be very clearly stated.
Question: Should the customer expect to hear from the foundry before they start producing the casting?
Porfilio: Once the foundry completely reviews the buyer’s contract, they should respond with an acknowledgement. This is the foundry telling the customer, ‘I’m going to heat treat the part like this, I’m going to follow this material spec, traceability will be enforced like this, I’m going to stamp heat numbers or ink mark them, and any other special processes required for the order. Even if the buyer has not requested a material certification or certificate of conformance, it’s good business practice for the foundry to communicate what they’ve interpreted and what they’re going to do. If the foundry doesn’t hear back from the buyer, they will go into production and build to that contract, purchase order, specification, and drawing. CS