This precision trapezoidal (metric) lead screws pitch and diameter are a perfect combination of high torque and speed. This screw fits the bill for most machine designs and will quickly become a standard on OpenBuilds.
Equipped with a large diameter that helps eliminate whipping and a high pitch which provides a quick 8mm translation for every revolution on the screw. 
It's a great power transmition choice for your next build.
Tr8*8-4
Lead Screw Diameter ∅ 8 (mm)
Pitch 2 (mm)
Lead 8 (mm)
Stainless Steel
An example steps settings for your control software would be 200 steps per millimeter if you are running your steppers at 1/8 step mode.
To calulate the steps for your control software have a look at these handy steps calculators 
 
 
Lead Screw Lengths
Actual lengths have been extended to allow for different connnection points.
290mm
540mm
1040mm
 
Please Note: The leads have a very slight larger diameter then the ID of the bearings. It is a very small difference and insures that the bearing has no to little axial play once the lead is inside.  You will want to take very fine sand paper (like 220 grit) and sand the ends of the Lead Screw about 2” in from each end to allow your bearing a nice fit to slip onto the ends of the lead.
Use with the V-Slot Nut Plate and Nut Block 
Also related parts: 8mm Lock Collar and 8mm Shim 
Lead Screw example build models Example 1 - Example 2
Please note: Other part models in various formats can be found in the Resources/Parts section of OpenBuilds.com