Why Does SWRCH10A Become SWCH10A? Where Did the "R" Go?
Many customers, upon first seeing Creation Group’s material certificates, can’t help but smile and ask us:
"Why does the steel mill’s certificate list SWRCH10A, while your finished product inspection report shows SWCH10A? Where did the R go?"
Every time we encounter this question, we always start by answering in all seriousness:
"The R? Of course, we ate it!" 😄
Customers usually laugh. However, beneath the humor lies a more interesting truth.
Serious Nonsense
Within Creation Group, there has long been an “industry secret”:
The steel mill produces wire rod (Rod), where the letter R stands for the rod’s identification mark.
When the wire rod arrives at Creation Group, it undergoes:
- Acid pickling
- Drawing
- Spheroidizing annealing
- Phosphating
- Lubrication
- Final finishing
After this series of processes, the R finally fulfills its historical role—and so… we “eat” it.
In the end, what reaches the customer is no longer ordinary wire rod, but high-quality cold heading wire (Wire) ready for direct use. Thus, the R retires with honor.
The Real Technical Reason
Of course, the above explanation is just an industry joke. The real reason stems from the grade definitions outlined in Japanese Industrial Standards (JIS).
Carbon steels for cold heading are divided into two distinct standards based on their product form:
Stage One: Hot-Rolled Wire Rod from Steel Mills
Standard: JIS G 3507-1
Grade designation: SWRCH
Examples include:
- SWRCH6A
- SWRCH8A
- SWRCH10A
- SWRCH22A
Here, the R stands for Rod, indicating that the product remains hot-rolled wire rod.
Stage Two: Cold Heading Wire (Finished Cold Heading Material)
Following acid pickling, drawing, spheroidizing annealing, phosphating, and other processing steps, the product transitions from Wire Rod to Cold Heading Wire.
The applicable standard becomes JIS G 3507-2,
and the grade changes accordingly to:
- SWCH6A
- SWCH8A
- SWCH10A
- SWCH22A
At this point, the R naturally disappears—not because it was removed, but because the product has shifted from Rod (wire rod) to Wire (cold heading wire).
What Does JIS G 3507 Specify?
JIS G 3507-2, titled “Carbon Steels for Cold Heading,” explicitly states that the grade designation for Cold Heading Wire shall adopt the corresponding Wire Rod grade, omitting the third letter R.
For example:
| Steel Mill Raw Material (JIS G 3507-1) | Reprocessed Finished Product (JIS G 3507-2) |
|---|---|
| SWRCH6A | SWCH6A |
| SWRCH8A | SWCH8A |
| SWRCH10A | SWCH10A |
| SWRCH22A | SWCH22A |
Therefore, the R is not omitted; rather, due to the change in product form—from Wire Rod to Wire—the R must be dropped according to JIS standards.
Why Do Some Suppliers Still Use SWRCH10A?
In the industry, you’ll often still see reports listing spheroidized cold heading wire as SWRCH10A.
Strictly speaking, this practice merely follows the original steel mill grade. According to JIS G 3507, for products that have completed cold working and are delivered as Cold Heading Wire, using SWCH10A is more standardized and accurately reflects the actual condition of the material.
How Does Creation Group View This Issue?
For us, although the letter R may disappear, the value of the product actually increases.
After all, what truly determines the quality of a coil of cold heading material is never the presence or absence of an extra letter in the grade designation, but rather every step of the subsequent manufacturing process:
✔ Thoroughness of acid pickling; ✔ Rationality of wire drawing; ✔ Uniformity of spheroidized microstructure; ✔ Stability of surface treatment; ✔ Consistency of mechanical properties; ✔ Compliance with customer requirements for cold heading, cold extrusion, and subsequent heat treatments.
So, if someone asks again, “Where did the R go?”
You can confidently reply with a smile: “The R hasn’t disappeared—it simply fulfilled its role as wire rod and has officially retired. The rest is up to Creation Group, which transforms it into high-quality cold heading wire.”
💡 Fun Fact (Based on JIS Standards)
According to JIS G 3507, “Carbon Steels for Cold Heading”:
- JIS G 3507-1 applies to carbon steel wire rod (Wire Rod), designated SWRCH.
- JIS G 3507-2 applies to carbon steel cold heading wire (Wire), designated SWCH, formed by removing the third letter “R” from the corresponding wire rod grade to distinguish product forms.
Thus, the transition from SWRCH10A to SWCH10A does not indicate a change in the material itself, but rather reflects the adoption of different grade designations under JIS standards as the product evolves from hot-rolled wire rod to cold heading wire.