| Tip Style
Materials - BeCu vs. Steel
QA Technology tip styles are manufactured from beryllium copper
and steel. They are heat treated for durability and plated with hard
gold to eliminate surface oxides and to lower electrical resistance.
We offer a wide range of standard point styles to cover a variety of
Diagram A compares the electrical performance of 100-25 series
probes with beryllium copper and steel plungers with gold plating.
There is a slight but measurable difference in the average resistance
between the two base materials. The steel plungers average 5 or 6
milliohms higher resistance than the equivalent tip styles made of
BeCu. Note that the bulk electrical resistance of BeCu is .08 microO-
meters at 20°C, while the steel in QA tip styles are .18 microO-
meters. Although steel has about twice the bulk resistance of BeCu,
the difference it makes in probe resistance will not affect the vast
majority of test applications. The hardness of steel plungers typically
ranges between 58 and 60 on the Rockwell C scale, versus 38-42 for
beryllium copper. Steel tip styles will, therefore, remain sharp longer
than BeCu plungers.
In cases of heavy side loading over many cycles, testing shows
virtually no difference in wear between BeCu and steel tip styles.
Sixteen pieces each of 100-PRP2524S and 100-PRP2524S-S were
run for 500,000 cycles at two-thirds travel against a contact surface
angled 30º from horizontal. There was no difference in life between
BeCu and steel, see Diagram A and Table A.