A magnesium ingot COA should demonstrate that a named lot meets the ordered composition. It should not be treated as interchangeable with a general product brochure.
Check identity before chemistry
Confirm the product grade, lot number, production or inspection date and quantity represented. The COA should be traceable to the physical bundles or pallets through markings and shipping documents.
Read minimum and maximum correctly
Magnesium is normally stated as a minimum, while individual impurities are stated as maximums. Mg99.95 and Mg99.90 therefore require a complete table. A high magnesium result does not excuse an individual impurity that exceeds its agreed maximum.
The Zhonghao catalog lists magnesium and separate limits for manganese, aluminum, zinc, copper, nickel, iron, silicon, tin, calcium and other elements. Buyers should use the product-page table as a procurement reference and place the final agreed limits in the purchase specification.
Identify the critical elements for the application
The downstream process determines which impurities need the tightest control. Aluminum-alloy producers, magnesium-alloy producers and steel-treatment operations do not necessarily use the same acceptance logic. Mark critical fields in the RFQ so that the supplier and laboratory understand the required reporting scope.
Confirm the test and sampling system
Ask which test method and equipment were used, who sampled the lot and how the sample represents the shipment. If an independent result will govern payment or acceptance, name the laboratory, sampling point and retest procedure in advance.
COA acceptance checklist
| Item | Confirmation |
|---|---|
| Grade | Matches the purchase order |
| Lot identity | Matches bundle and shipment markings |
| Mg result | Meets the agreed minimum |
| Individual impurities | Each meets its agreed maximum |
| Method and laboratory | Accepted by both parties |
| Signature/date | Report is controlled and current |
The COA is one part of receiving control. Bundle condition, weight, markings, packing and any surface-quality requirements should be inspected separately.
Source register
- Zhonghao formal product catalogue, page 4, Magnesium grade composition
- Standard background: GB/T 3499-2023 primary magnesium ingot overview, https://mp.weixin.qq.com/s/zw902YlxUdFSh8WCxcgrBA
- Reference-material background: https://mp.weixin.qq.com/s/D2vIiR8upTxRkaolfkHShA