The exact ordering of metal castings takes a certain amount of time and also energy to qualify a potential supplier foundry. To get the best value with the metal casting also requires a cooperative effort on the part of the shopper and the supplier foundry from the early stages of the design before the end manufacturing process. Good planning ahead of time will pay profits for both you (the customer) and your supplier foundry.
The purpose of requesting a quotation for a steel casting is really to determine the lowest purchased casting cost. The customer then will have to weigh all of the provisions of the quotation including exceptions taken up to drawings, specifications, and processing requirements, as well as supplier foundry experience, tooling requirements, tolerances, finish allowances, and sending. Such factors as reduced machine work, better tolerances, improved delivery schedules and reliability are particularly important to ascertain the lowest end cost of the casting.
To avoid misunderstandings, keep your charges down, and expedite the processing of quotations, all or most of the following information should be included in a request for a estimate:
- Design – What is the part? See DESIGN below.
- Range – What is the anticipated or required volume, both offer and future?
Material and inspection requirements; what if the part be made of, and how should the part be put into practice before delivery? ASTM or other nationally recognized specific features should be used whenever possible to identify the material and inspection necessities. See MATERIAL
SPECIFICATIONS and SOUNDNESS below.
Actual or simply estimated casting weight. Actual weight information is desired. Estimates can be provided by the supplier foundry in the lack of actual weight information, but this may require offering price tags that are subject to changes based on the actual weight of the casting(s) in question at the time of production.
Drawing. Machine drawings are recommended over casting drawings. Drawings or sketches are essential if samples or patterns are not available. Drawing include dimensional tolerances, indications of critical areas and floors to be machined. See MACHINING below.
Pattern. If shapes and core boxes are available, the request for a offer should indicate the type, condition and set up of the equipment. Discover PATTERNS below.
Production/delivery schedules required. Present and estimated need should be included in quotation requests.
Beyond these concepts, there are levels of customer requirements that could include supplier foundry liabilities, which affect the casting cost drastically. These may possibly include receiving inspection acceptance and back charge protection plan, casting return policy, expediting procedures, and sophisticated adjustments not normally associated with the standard inquiry. A complete understanding of most of these areas is best developed by an open relationship between the customer as well as the supplier foundry representative, and the professional attitudes and goes through that both can provide during the quotation evaluation phase.
To achieve the most efficient production and the highest quality product, the part need to be designed to take advantage of the flexibility of the casting process. The dealer foundry must have either the designer’s drawings or habit equipment and know the length of the run (number of portions to be made).
Castings are generally furnished with un-machined as-cast surface types, unless otherwise specified. To take advantage of the casting process, the exact supplier foundry should also know which surfaces are to be machined and where datum points are located. The acceptable dimensional tolerances must be indicated when a drawing is provided. Tolerances are normally decided by agreement between the supplier foundry along with customer. Close cooperation between the customer’s design engineers plus the supplier foundry is essential to optimize the casting pattern.
Industry standard specifications provide the casting shopper with the tools necessary to establish criteria for almost any casting applying it. These specifications do not preclude special requirements that the buyer’s technical staff members may require. Variations from standard specifications can cause misunderstandings, higher costs and disqualification of potential company foundries. If exception is taken to a provision generally body of a specification requirement (as opposed to taking exception to this rule to a supplemental requirement of a specification), the resulting casting can’t be held to compliance with that specification.