Spring Force

Probe Selection

QA Technology offers many combinations of probes. You can build your probe by selecting the tube style, tip style and spring force for your specific application.

If you have questions at any time during the process, contact us at (603) 926-0348.

Begin building your part number.

NOTE: P has already been selected for you as the default tube material.

Letter	Material	Average Resistance			Current Rating¹ SS @ 204°C
P	Nickel silver/ID precious metal clad	< 75 milliohms			3.6 Amps

Next: Choose your Tip Style.

Select your tip style. Standard material is heat-treated BeCu/plated gold over nickel.
Choose

for steel plungers, if available.
Use the drop-down menu at right to filter your choices by target type.

Next: Choose your Spring Force.

Select your spring force.

Letter	Spring Force	Preload	@ .317 [8.05] Stroke	Material	Cycle Life @ .317 [8.05] Stroke
S	Standard	0.7 [20g/0.19N]	4.0 [113g/1.11N]	SS	50,000
H²	High	1.8 [51g/0.50N]	6.0 [170g/1.67N]	SS	50,000

Next: Choose applicable Options.

Select your option (if required).

Letter	Description - no options are required.
D	Decreased stroke is .250 [6.35]. Must select from 039-25 Series spring forces with this option.
N	No probe lubrication. Removing probe lubrication greatly reduces cycle life and should only be used in applications requiring operating temperatures below -45°C.
	Heat treated steel/plated gold over nickel (see tip styles for availability)

You may add your Part Number to your Order.

¹Current Rating is affected by spring material and lubrication choices. Standard lubrication has a 204°C maximum operating temperature limit.
Before using probes near these current limits, please refer to Current Carrying Capacity and Operating Temperature Application Notes.

² .350 [8.89] max stroke for H spring

All specifications subject to change without notice. All dimensions are in [mm]. All spring forces are oz [gm]. US Patent No. 4,885,533