FDHT Spring Tester
Force Digital Hand Tester

The FDHT is a tension / compression tester with force measurement only. It is equipped with a high-resolution force measuring system to display current or peak force and can be fitted to perform a variety of force tests.

  • 18″ standard range
  • Standard 7″ stroke
  • Up to 4″ Ø platform (2″ standard)

FDHT – Force Digital Hand Tester








The FDHT is a tension / compression tester with force measurement only. It is equipped with a high-resolution force measuring system to display current or peak force and can be fitted to perform a variety of force tests. Standard pull lengths of 12” can be increased with optional extended rods to up to 48” to test long parts. It has a rugged cast-aluminum and steel frame, precision rack and pinion drive with adjustments for wear and convenient hand operation to apply force and adjust length.













Includes Length Deflection Compensation

What is length deflection compensation?
All force/lengh testing devices, regardless of manufacturer, have additional deflection by the load cell and tester frame which occurs as the spring is loaded. If you buy/use a tester without deflection compensation, measurements might include significant length errors.
Spring deflection, also known as spring travel or motion, is the action of a compression spring compressing (being pushed), an extension spring extending (being pulled), or a torsion spring winding (being twisted) when a load is applied or released. This is one characteristic (spring deflection) that is measured by a Larson Systems Spring Tester.

Larson Systems has BUILT-IN Length Deflection Compensation so that the user does not have to calculate and apply length corrections. Most competitors do not have length deflection compensation.

With a Larson Systems product, forget about calculating load cell and frame deflection when testing, we’ve got you covered.

SDC Software Demo

Try our software for “Spring Testing Data at Your Fingertips”. With Larson System’s SDC Software, your spring testing data can be accessed, stored and manipulated as it is generated. Store specifications for different parts, load a set of parameters and clearly see which springs are out of spec using the on-screen graphical representation of the testing results. Save and print results or open the results file in Microsoft Excel. You have complete control of your testing data.

Free Demo

Force Specifications

Load Cell
Standard Resolution High Resolution*
0-100% FS 0-20% FS 20-100% FS
2 lb 0.001 lb 0.0001 lb 0.001 lb
907 g 0.2 g 0.02 g 0.2 g
8.9 N 0.002 N 0.0002 N 0.002 N
11 lb 0.005 lb 0.0005 lb 0.005 lb
5 kg 0.002 kg 0.0002 kg 0.002 kg
49 N 0.02 N 0.002 N 0.02 N
22 lb 0.01 lb 0.001 lb 0.01 lb
10 kg 0.005 kg 0.0005 kg 0.005 kg
98 N 0.05 N 0.005 N 0.05 N
66 lb 0.02 lb 0.002 lb 0.02 lb
30 kg 0.01 kg 0.001 kg 0.01 kg
294 N 0.1 N 0.01 N 0.1 N
110 lb 0.05 lb 0.005 lb 0.05 lb
50 kg 0.02 kg 0.002 kg 0.02 kg
489 N 0.2 N 0.02 N 0.2 N
200 lb 0.1 lb 0.01 lb 0.1 lb
91 kg 0.05 kg 0.005 kg 0.05 kg
890 N 0.5 N 0.05 N 0.5 N
750 lb 0.5 lb 0.05 lb 0.5 lb
340 kg 0.2 kg 0.02 kg 0.2 kg
3,336 N 2 N 0.2 N 2 N
Accuracy = ± Full Scale Resolution x 2
*Requires High Resolution Force option 050-0000-0107-00

Parts and Accessories


DescriptionPart Number 
FDHT - 2 lb Force Digital Hand Tester050-0000-0047-01Get a Quote
FDHT - 11 lb Force Digital Hand Tester050-0000-0047-02Get a Quote
FDHT - 22 lb Force Digital Hand Tester050-0000-0047-03Get a Quote
FDHT - 66 lb Force Digital Hand Tester050-0000-0047-04Get a Quote
FDHT - 110 lb Force Digital Hand Tester050-0000-0047-00Get a Quote
FDHT - 200 lb Force Digital Hand Tester050-0000-0047-05Get a Quote
FDHT - 750 lb Force Digital Hand Tester050-0000-0048-00Get a Quote

Factory and Accuracy Options

DescriptionPart Number 
High Resolution Force (10X Resolution from 0-20% FS)050-0000-0107-00Get a Quote
Micro Length Adjust with Built-in Stops (CDHT, DHT)025-0000-0407-02Get a Quote
MicroAdjust Wrenchless Stop Assembly025-0000-0676-00Get a Quote
Quick Release Range Adjust Handles (200 lb Max Load)025-0000-0412-00Get a Quote
RS232 / USB output, DHT Family050-1000-0064-00Get a Quote


DescriptionPart Number 
Spring Button Platform - 1" Ø (Hardened steel)018-0000-0914-01Get a Quote
Platforms - 4" Ø (Pair for 5/16-18 Mount)025-0000-0191-00Get a Quote
NiCad Rechargeable Battery (4-8 hr life)025-1000-0654-00Get a Quote
Single Stop Rod025-0000-0293-00Get a Quote
Double Stop Rods025-0000-0333-00Get a Quote
Extension Spring Swivel Wire Hook - 2 lb cap (0.030" Ø wire)025-0000-0340-05Get a Quote
Extension Spring Swivel Wire Hook - 2 lb cap (0.050" Ø wire)025-0000-0340-06Get a Quote
Pin Extension Hooks025-0000-0250-04Get a Quote
Wire Extension Hooks025-0000-0523-00Get a Quote
Machined Extension Hooks025-0000-0250-03Get a Quote
Wire Crimp Pull Fixture - Upper, 1/32 to 7/16 slot width025-0000-0271-00Get a Quote
Wire Crimp Grip Fixture - Lower 110 lb025-0000-0274-00Get a Quote
Wire Crimp Grip Fixture - Lower 1,000 lb025-0000-0272-00Get a Quote
Smooth Jaw Wire Chucks - 100 lb025-0000-0193-00Get a Quote
Serrated Jaw Wire Chucks - 200 lb025-0000-0193-01Get a Quote
Smooth Jaw Wire Chucks - 400 lb025-0000-0193-02Get a Quote
5/16-18 M to 10-32 M/F Thread Adapter018-0000-1718-00Get a Quote
5/16-18 M to M6 M/F Thread Adapter018-0000-1718-01Get a Quote
5/16-18 M to M4 M/F Thread Adapter018-0000-1718-02Get a Quote
Dust Cover - 18" Range Rods (FDHT, DHT, SDHT)059-1000-0012-00Get a Quote
Rubber Mounting Foot Upgrade025-0000-1310-00Get a Quote
Solid Height (Coil Bind) Protector - 2" 018-0000-4358-00View Product

RS 232 Options

DescriptionPart Number 
Inkjet Printer (Includes Parallel to 9pin RS 232 Adapter Cable)025-0000-0464-02Get a Quote
RS 232 to Parallel Printer Cable / Adapter (DB9)025-0000-0458-01Get a Quote

Software Options

DescriptionPart Number 
SSS - Statistical & Spreadsheet Interface Software050-0000-0075-00Get a Quote
Spring Data Collector Software (for use with DHT family testers)050-1000-0060-01Get a Quote

Power Supplies

DescriptionPart Number 
Power Supply, 100-240 VAC 50-60 Hz (USA Plug)025-1000-0396-00Get a Quote
Power Supply, 100-240 VAC 50-60 Hz (International Plugs)025-1000-0396-04Get a Quote