Round Cartridge Spindles


Select your spindle and pulley types for pricing.
Spindle Options: 3/4-16 #1M taper or ER-16
Pulley Options: Cog or 2-step V

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    Nickel/Teflon plating

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About the Industrial Round Cartridge Spindles

The cartridge spindle bodies are turned from bar stock steel and have a black oxide finish. The steel spindle shaft has a .405″ (10mm) hole through the center. They are available with your choice of a spindle (3/4-16 #1M taper or an ER-16*) and pulley configuration (a standard 2-step “V” belt pulley or a 30-tooth cog belt pulley).

All Sherline Industrial spindles feature lifetime lubricated bearings with adjustable preload. The bearings are Class 5 for better accuracy, tighter tolerance, smoother and quieter movement, and cooler running. The bearings in all our industrial headstocks, except for the 3C headstock, are 6004-VV C3P5 – ABEC 5. The headstock bearings are rated for a continuous speed up to approximately 4,000 RPM with factory preload adjustment of .0002″. You may need a slightly looser preload setting of .0003” for operating speeds up to 10,000 RPM.

*NOTE: We do not sell the collets used with the ER-16 spindle. Those are available through MSC Industrial Supply Co. or other tool supply sources.

Standard Features

  • Spindle bearing dust cover washer
  • ER-16 collet nut ships with the ER-16 spindle headstocks

Installing the Round Cartridge Spindle

The Sherline round cartridge spindle has an OD of 2.2495″–2.2500″ on the cartridge. This cartridge is designed to be mounted in a 2.250″–2.252″ diameter hole.

Optional Nickel/Teflon Spindles

Most of our spindles are available with a Nickle/Teflon plating as a rustproof option for an additional cost. Check the option box above to add the Nickel/Teflon plating to your spindle order.

Spindle Precautions

These spindles should be considered light duty. A .405 (10 mm) through hole allows long stock to be passed through the spindle. This design provides a lot of versatility but was not intended for long or out-of-round parts to be rotated at high RPM. It is up to the operator to determine if the spindle and the setup are adequate and safe for the job being attempted.

The spindle is equipped with a dust cover, but it is not totally sealed. The presence of dust from grinding operations can shorten bearing life considerably. It was also not designed to be operated in a coolant bath. The spindle shaft should be shielded from coolant spray.

The improper use of machine tools and their accessories can result in serious injury. Before using this tool, thoroughly read the instructions and make sure you understand its proper and safe use.


Always wear safety glasses when operating machine tools.

Download PDF Industrial Round Cartridge Spindle Instructions

Instructions PDF Download

Spindle diameter: 2.250″ (57.15 mm)
Spindle body length: 3.0″ (76.2 mm)
Hole through spindle .405″ (10 mm)
Spindle nose thread (Models 6509, 6510) 3/4-16
Spindle nose internal taper (Models 6509, 6510) #1 Morse
Spindle nose thread and taper (Models 6511, 6512) ER-16
Bearings (2) 20 mm, class 5, lifetime lubricated ball bearings with adjustable preload
End play (factory preload adjustment) .0002″ (.0051 mm)
Maximum spindle speed 10,000 RPM
Recommended continuous spindle speed 4000 RPM or less
Mounting provision None. This cartridge is designed to be mounted in a 2.250″–2.251″ diameter hole.
Part No. Description Quantity
31080 10-32 x 3/8″ Flat Point Set Screw 1-2*
40160 Preload Nut 1
40230 3/4-16/#1 Morse Spindle (used on P/N 6509, 6510) 1
40320 Bearing Dust Cover Washer 1
40420 Class 5 Headstock Bearings 2
40440 #2 x 1/4″ Self-Tapping Phillips Head Screws 2
40600 10-32 X 1/4″ Flat PT Set Screw 2
43230 2-Step V-Belt Pulley (used on P/N 6510, 6512) 1
65016 30-T Timing Belt Pulley (used on P/N 6509, 6511) 1
65041 2.25″ Round Cartridge Spindle Body 1
65023 ER-16 Spindle (used on P/N 6511, 6512) 1
65026 ER-16 collet nut (used on P/N 6511, 6512) 1

*1 set screw required for pulley on P/N 6510 and 6512, 2 set screws used on cog pulley, P/N 6509 and 6511

Click the P/Ns below to download a zipped version of the IGS 3D CAD file. You will need to extract the zip file before viewing the IGS file.
6509 3D IGS model
6510 3D IGS model
6511 3D IGS model
6512 3D IGS model
You need an IGS viewer to view .igs files. CLICK HERE to download a FREE IGS viewer.