Product Description

803-E Invar Kit

When relative measurement is all you need to do

Our special 803-E Invar Kit gives you an economical way to create scale extensions, or build certain types of calibration artifacts, when the only thing that’s important is that the length doesn’t change between measurements. We call this type of kit “extension grade” because the length tolerance on the Invar bars is relatively big (±0.050″, or ±1.27mm). The bars are not calibrated, certified, or serialized. They are simply designed to give you an economical way to hold your scales or other targets while making relative or comparative measurements, but still provide you the benefit of the low thermal coefficient properties of Invar. These properties effectively eliminate changes in length due to handling or environmental fluctuations.
Invar Tubes 12473 Series
Tube Length Tolerance ±0.050″ (1.27 mm)
 Individual components may be assembled to produce lengths from 2″ to 112″, in 5″ increments. The end of each invar tube allows measuring to the tangents of shafts, and a tooling ball contact point offers the best repeatability on most machine surfaces. A concave tip is included for use with tooling ball applications.
The table below specifies all included components. Be sure to have a look at our other Invar System components.

803-E Invar Kit Components

Legend Part Number Description Qty
A 12473-20IN 20″ Invar Tube 4
12473-10IN 10″ Invar Tube 2
12473-5IN 5″ Invar Tube 2
B 12410-G2 Concave Tip 2
C 12410-G1 Tooling Ball Tip 2
D 8665-G1 Fixed Scale Holder 2
E 12406-G1 Stainless Steel Invar System Connectors 10
no photo 12421-G1 Plastic Case 1
no photo NIST Traceable Certification for Kit 1

May Be Used With

Any of our optical tooling scales except for the 6040 and 6100


Approx. weight: 
Kit and case, 17 lbs. (7.7 kg)
Shipping, 22 lbs. (10 kg)
Invar thermal expansion coefficient:
0.68 x 10−6 in./in.°F for temperature range of 0-200°F (1.26 x 10−6 m/m/°C for temperature range of −18°C to 93°C)
Invar tubing:
1″ diameter Invar with stainless steel end caps, having 3/8″-24 internal threads on each end
Finish: Oil and stain resistant PVC jacket, black in color
Case: Plastic case with foam insert