Cast Iron Price Guide

As for buyers for cast iron casting products, a price guide is necessary for evaluating the quotations from suppliers.

However, cast iron price is a complex issue, because an accurate price is related to many aspects, such as rough casting weight, cast iron material grades, heat treatment, production processes, machining works, surface coating and anti-rust protection, also need to considerate the technical requirements to the material, dimensional tolerance and casting defects.

Herein, we try to summarize the composition of an accurate quotation, and all related concerns. This guide can not make you become an price expert, but at least, it could help you to understand the quotations.

1. Cast Iron Material Grades

The production costs for different cast iron grades are different. For example:

• Ductile iron is more expensive than gray iron

• Higher material grades are more costly than lower grades

Please refer to our article Cast Iron Grades to learn about the material grades.

Tips: Before you place the inquiry, please check if you have denoted the cast iron grades in the inquiry or on the drawings.

2. Casting Production Processes

The cast iron casting prices have been seriously affected by production processes. For example:

• Shell molding process is the most expensive.

• Furan resin coated sand casting process is more costly than green sand.

• Green sand by manual and molding equipments is the cheapest casting process.

As for the difference of these sand casting processes, please refer to our article Sand Casting Process.

Tips: Check what casting processes your supplier will be used to produce your parts. Suitable and cheap casting process will be the good choice.

3. Rough Casting Weight and Machining Allowance

Some buyers did not care about the unit weight, but the unit weight is very important to prices. The unit weight of rough castings are the base of rough casting prices. The rough weight is also related to the machining allowance. Larger machining allowance will cause larger of rough weight.

Tips: If you know the rough weight or machined weight, you should tell your supplier during quotation, otherwise, their quotation will not be accurate, which may cause your trouble in the future.

4. Machining Tolerance and Costs

Higher and tighter machining tolerance will require more complex and high precision machining equipments, so will cause higher machining costs.

Tips: Denote as detailed as possible for machining tolerance and surface finish requirements, which will help your suppliers to quote an accurate machining costs.

5. Extra Heat Treatment Requirements

As for the low and middle grades of gray iron, ductile iron and carbon steel castings, no need for extra heat treatment, so no need to consider the heat treatment costs either. However, as for the high grades or alloy steel castings, the extra heat treatment costs should be considered. Such as the hardening and tempering, or called as quenching treatment.

Tips: Both buyers and suppliers should pay attention to the hardness requirements, which may cause the extra heat treatment costs.

6. Pattern Types and Costs

There are several types of patterns used to produce metal castings, such as iron patterns, aluminum patterns, resin pattern (also called as plastic pattern) and wooden patterns. The patterns should be chosen according to the quality requirements, annual demand and production processes. Different patterns will cause very different costs, so need to be paid attention to during quotation.

As for the various pattern types and their costs, please refer to our article pattern for casting process.

Tips: Ask your supplier to denoted the pattern types in the quotation, then evaluate if they have chosen the suitable patterns.

7. Price Influence of Annual Demand and Unit Weight

• Annual demand is small, then their unit price will be higher.

• Annual demand is large, then their unit price will be lower.

• Unit weight is small, then their price per kg will be higher.

• Unit weight is large, then their price per kg will be lower.

Tips: Normally, the casting foundry will not offer you any discount if you increase the annual demand. The annual demand is just an important reference during quotation, but it will not bring you an discount.

8. Complexity of Casting Design

More complex casting will mean more moulding work time, and more materials for sand cores, also more higher defective rate. So, the complexity of casting design will cause big difference to prices.

9. Dimensional Tolerance Requirement

Both dimensional tolerance requirements to rough castings and machining will be good reference for suppliers to consider the suitable casting production processes, and machining equipments, so they will affect the related casting and machining costs too.

Tips: The buyers should clearly denote all dimensional tolerance requirements on the drawings.

10. Extra Requirements to Cast Iron Materials

If there are only material grades on the drawings, and requirements, then the material will not be a problem for the suppliers to understand the technical requirements, however, for special application, the cast iron parts may need extra requirements to the materials, such as to the nodularity rate, pearlite content, carbon residue content, hardness etc. These extra requirements will affect the production process, raw iron material or alloy nodulizing agent etc. So, affect the casting prices.

Tips: Buyers should clearly denote all material requirements on the drawings or in the requirement documents, and should inform their suppliers if it is necessary.

11. Surface Finish Smoothness to Rough Casting and Machined Surfaces

The requirements to the surface finish smoothness degree to rough castings and machined surfaces will cause the selection to the casting process processes and machining works, so affect the prices to the machined parts.

As for the comparison of the machined surface finish degrees, please refer to our article Machining surface finish chart, comparator, method, degree, Ra, Rz, RMS.

12. Surface Coating and Anti-Rust Protection

As for the normal anti-rust primer painting, normally, the suppliers will be able to consider and include their costs in the quotation. This cost is only about 0.05 USD/kg based on the casting weight. However, if the buyers have the requirements to the special coating and painting, such as finish painting, zinc plating, hop dip galvanizing, anti-heat coating, powder coating, electophoretic coating etc, then the coating cost will be much more higher.

Tips: The buyers should denote the requirements on the drawing or in the inquiry, and notice if the manufacturers have considered these costs in the quotation.

13. Casting Defects Requirements to Outside Surface and Inside Areas

As for sand molding castings, casting defects are inevitable. Some on the surfaces, some inside. So, the requirements to the defects are also an important influence factors to the prices.

Higher casting defects requirements will cause higher production costs, and will cause the higher defective rate before delivery.

Tips: If the buyers have special requirements to the casting defects, you should tell the suppliers in advance.

14. Exchange Rate of Currency Influence

As for all metal foundries in China, the production costs and prices were calculated by RMB currency. When they made the quotation, they just change the RMB into USD according to the exchange rate.

If the exchange rate has certain change, then the suppliers will request to adjust the price by USD, so it is also a main factor to the prices of castings.

Of course, if the change will be benefit to buyers, then the buyers can request to adjust the prices too.

Tips: Require your suppliers to denote the exchange rate in the quotation, it will be useful when the price adjustment.

Summary

All these above factors will affect the final price of castings, so unless the casting is extremely simple, otherwise, it will not be easy to make a accurate price evaluation by buyers.

I think, as for buyer, you should denote or inform all necessary requirements, and check if the suppliers have considered them during quotation.

On the website of Dandong Foundry, we update the gray iron, ductile iron and cast steel prices timely according to the current production costs.

Home | More Articles