C17200 vs. C17300 Beryllium Copper Wire

What to Confirm Before Specifying Alloy 25

By the time a buyer is looking at Alloy 25 beryllium copper wire, the broad material search is usually over. The question is no longer whether ordinary copper wire will work. The question is whether the request gives enough detail for the supplier to produce the wire the part needs. That is where C17200 and C17300 create a practical decision point.

C17200 and C17300 are both listed by Little Falls Alloys as heat treatable Alloy 25 beryllium copper wire. They sit close enough together that a buyer may assume the choice is minor. It is not minor when the print, tensile range, heat-treatment condition, wire form, plating requirement, or the next production step depends on it. For Alloy 25 wire, the alloy designation is the first decision, but it is not the full specification.

Why Alloy 25 Requests Go Wrong

A request for “Alloy 25 wire” sounds specific, but it may still omit the details that govern the finished material. The buyer may know the part requires heat-treatable beryllium copper wire, but the supplier still needs to know the condition, form, dimensions, and final requirements. A round wire requirement is not the same as a rolled flat wire requirement. A wire needed before precipitation heat treatment is not the same as wire needed after precipitation heat treatment.

This matters because Alloy 25 is often selected for performance-critical reasons. The wire may need strength, spring properties, conductivity, corrosion resistance, stability, and low creep. Those properties depend on the correct alloy and the correct processing path. If the request only provides a broad material name, it may not indicate whether the wire needs to be formed, heat-treated, plated, straightened, cut, or held to a final tensile target.

A complete Alloy 25 wire request should specify details that affect the finished wire, not just the alloy family.

• Alloy designation, such as C17200 or C17300
• Material callout, such as Alloy 25, Alloy 125, BeCu, or beryllium copper
• Wire form, such as round, half-round, square, or rolled flat
• Diameter, width, thickness, or profile dimensions
• Condition as supplied, if specified
• Heat-treated condition, if specified
• Tensile strength requirement in KSI or MPa
• Heat treatment requirement, if listed
• Plating requirements, such as gold, silver, nickel, copper, or tin
• Straightened and cut requirement, including length, tolerance, and quantity

The goal is not to make the request longer. The goal is to make it complete enough to match the finished part requirement. A short request with the right data is more useful than a long request that only says, “beryllium copper wire.”

The First Choice, C17200 or C17300

C17200 and C17300 both appear under Little Falls Alloys’ heat treatable beryllium copper Alloy 25 data. The key composition difference shown in our data is the lead range for C17300. C17300 includes lead at .20 to .60, while the shared composition data for C17200 and C17300 lists copper, beryllium, cobalt and nickel, iron, silicon, and aluminum limits. That lead callout is the practical difference a buyer should notice when comparing the two designations.

C17200 is the standard Alloy 25 path when the print, material specification, or purchase order calls for C17200. If the requirement specifies C17200, the RFQ should also specify C17200. The buyer should not substitute C17300, as the two are in the same beryllium copper family. The drawing or customer specification controls the request unless engineering approves a change.

C17300 is the leaded (should this word be leading?) Alloy 25 path when the print, material specification, or purchase order calls for C17300. If a buyer sees C17300 in the requirement, that detail should be carried into the RFQ. The lead range shown for C17300 is not a side note. It is part of the material identity and should be confirmed before quoting.

The comparison is simple, but it should not be ignored.

Decision point	C17200	C17300
LFA category	Heat treatable Alloy 25 beryllium copper	Heat treatable Alloy 25 beryllium copper
Key composition difference shown by LFA	No C17300 lead callout	Lead listed at .20 to .60
Best action when listed on a print	Specify C17200	Specify C17300
Best action when request only says Alloy 25 or BeCu	Confirm the required UNS alloy	Confirm the required UNS alloy

If a buyer already has a print, the print usually answers the C17200 vs. C17300 question. If the request only says Alloy 25, Alloy 125, BeCu, or beryllium copper, the exact alloy should be confirmed before the job moves forward. That is the first layer of the decision, but it still does not finish the specification.

The Bigger Choice, Condition and Heat Treatment

The more important mistake is treating the alloy designation as the whole answer. For heat treatable Alloy 25 wire, condition changes the material in a way that matters to the finished part. Little Falls Alloys separates mechanical properties by condition as supplied and after precipitation heat treatment. Those ranges show why a request for C17200 or C17300 still needs more detail.

For round, half-round, and square wire, TB00 solution-annealed material is listed at 58 to 78 KSI as supplied. After precipitation heat treatment, TF00 is listed at 165-190 ksi. That is not a small adjustment. It changes what the buyer is asking for and what the wire is expected to do.

The same pattern continues through harder supplied conditions.

Round, half-round, and square wire example	As supplied tensile strength	After precipitation heat treatment
Solution annealed	TB00, 58 to 78 KSI	TF00, 165 to 190 KSI
Half hard	TD02, 110 to 135 KSI	TH02, 185 to 210 KSI
Hard	TD04, 140 to 165 KSI	TH04, 195 to 230 KSI
Extra hard	TD06, 155 to 180 KSI	TH06, 205 to 235 KSI

This is why “C17200 wire” or “C17300 wire” may be incomplete. The buyer also needs to communicate whether the wire is needed as supplied, after precipitation heat treatment, or to a specific tensile range. A customer who needs wire for forming may need a different supplied condition than a customer who needs wire tied to a final hardened strength range. The correct request depends on the part path.

Wire form also belongs in the same conversation. Little Falls Alloys publishes separate mechanical property data for round, half-round, and square wire, and for rolled flat wire other than square. A buyer should not assume a tensile range for one form applies to another. If the requirement is rolled flat wire, square wire, half-round wire, or round wire, that detail should be stated directly.

Heat treatment should be handled the same way. Little Falls Alloys lists standard specification treatment at 600°F, with time varying by designation and wire form. The data also notes that temperatures between 550°F and 700°F are used for special purposes, with corresponding time adjustments. The buyer does not need to calculate a treatment schedule from scratch, but the RFQ should include the heat treatment requirement if the print or process controls it.

Heat Treated Beryllium Copper Wire

For Alloy 25 wire, the right request is not built on the alloy name alone. C17200 vs. C17300 matters, but the finished wire also depends on condition, heat treatment, tensile range, wire form, plating, and any straightened-and-cut requirements. Little Falls Alloys brings those details together because beryllium copper has been a specialty since the metal’s commercial inception. The supplied condition tells us what the customer receives before further processing, while the precipitation heat-treated condition defines the final strength range. That is why a complete request should include the print, material callout, tensile requirement, wire form, dimensions, and any finishing or cut-length needs. When those details are clear, Little Falls Alloys can help connect the specification to the wire the part requires.