Abstract

Silver-clad copper (Sil-Cop) wire is often selected for use as medical extrusion core wire due to its

biocompatibility and elongation characteristics. However, it has been observed that the silver cladding may

flake when used in this type of application, leaving residue in equipment and finished catheters. An

alternative material, such as 300 series stainless steel, has comparable performance and compatibility. As a

single alloy wire, it eliminates the risk of flaking.

Introduction

The performance of stainless steel extrusion core wire was tested against Sil-Cop to compare overall

diameter profile, percent diameter reduction, and force requirements. Various sizes of each wire type were

put under an axial load and elongated. Once elongated, the diameter of the wire was measured at points

along the length of the sample. The force required to elongate and reduce the diameter of the samples was

also measured and compared.

Experimental Results

Test 1: Diameter Reduction

This test determined the overall diameter reduction profile of 300 series stainless steel and Sil-Cop.

Samples of both materials were elongated under an axial load and the diameter was measured to

determine which deformed more consistently. Diameter measurements were taken at intervals (every six

inches) along each wire and recorded. For comparison, a sample of each wire type is presented in Table 1:

Diameter Profile Comparison.

Table 1: Diameter Profile Comparison

We tested 0.015” 300 series stainless steel wire and observed the following:

 At 6”, the wire diameter measured 0.01265”

 At 12”, the wire diameter measured 0.01285”

 At 18”, the wire diameter measured 0.01285”

 At 24”, the wire diameter measured 0.01280”

 At 30”, the wire diameter measured 0.01275”

0.010

0.011

0.012

0.013

0.014

0.015

0.016

0.017

0.018

0.019

0.020

6" 12" 18" 24" 30" 36" 42" 48" 54" 60" 66" 72" 78"

Diameter (inches)

Measurement interval along elongated wire

Diameter Profile

.015" 300 Series .019" Sil-Cop