VERTEX 7-1/2″ SEMI-UNIVERSAL DIVIDING HEAD SET (3800-5810)

Professional Indexing Without Overloading a Smaller Milling Table

The Vertex BS-0 7-1/2″ Semi-Universal Dividing Head Set brings direct, indirect and calculated angular indexing to machine shops that need a more compact alternative to a full-size dividing head.

At a listed shipping weight of 45 lb, the BS-0 is easier to handle and occupies less milling-table space than the 74 lb Vertex BS-1. This makes it a practical option for smaller knee mills, compact toolroom machines and advanced workshop equipment where table capacity and available travel must be used carefully.

The set includes an adjustable tailstock, dividing plates, centers, drive dog and chuck-mounting backplate. Its hardened and ground spindle is supported in a tapered roller bearing, while the hardened worm mechanism provides controlled rotation with limited backlash.

Add true indexing capability to a compact milling setup without immediately moving to a larger, heavier dividing-head system.

Built for Compact Milling-Machine Setups

A dividing head must provide enough rigidity for the workpiece without consuming excessive table travel or placing unnecessary load on the machine. The Vertex BS-0 is designed for smaller indexing applications where the size and weight of a BS-1 or BS-2 may not be justified.

It is particularly useful for:

• Small and medium gear blanks.
• Compact shafts and arbors.
• Indexed drilling patterns.
• Multiple flats on round components.
• Small splines and serrations.
• Fluting and equally spaced grooves.
• Prototype and one-off components.
• Repair parts for automotive and industrial equipment.
• Advanced home and educational machine shops.

The nominal 7-1/2″ size should not be interpreted as a guaranteed gripping or swing capacity for every setup. Confirm the workpiece envelope, tailstock position, cutter clearance and optional chuck size before ordering.

Direct Indexing for Fast, Common Divisions

The BS-0 incorporates a 24-hole direct-indexing plate for rapid positioning in frequently used divisions.

Direct indexing can produce:

• 2 divisions at 180°
• 3 divisions at 120°
• 4 divisions at 90°
• 6 divisions at 60°
• 8 divisions at 45°
• 12 divisions at 30°
• 24 divisions at 15°

This method saves setup time when machining squares, hexagons, equally spaced flats, slots, grooves and simple drilling patterns.

40:1 Indirect Indexing for Additional Divisions

For divisions that cannot be produced by the direct plate, the BS-0 uses a 40:1 worm ratio with the included dividing plates.

Forty complete turns of the indexing crank rotate the work spindle once. The operator selects the appropriate hole circle and crank movement according to the required number of divisions.

The system supports easy indexing from 2 through 50 divisions and most commonly required divisions up to 380, depending on the available plate-hole combinations and indexing chart.

Possible indirect-indexing applications include:

• Gear-tooth spacing.
• Spline layouts.
• Serrations.
• Multiple keyways.
• Fluted tools and components.
• Bolt-circle drilling.
• Polygonal profiles.

Calculated Angular Positioning

The 40:1 worm relationship can also be used to position the spindle through a calculated angle. Because one crank revolution rotates the spindle by 9°, the operator can determine the required crank and plate movement for many angular layouts.

This is useful for machining features separated by a specified angle rather than a whole-number division.

Always verify the calculation, plate selection and starting position before cutting. A small indexing error is repeated around the complete part.

Tilting Head from −10° to 90°

The swivel head can be locked at any angle from 10° below horizontal through 90° vertical. This allows the workpiece axis to be positioned horizontally, vertically or at an intermediate angle.

The tilting range expands the BS-0 beyond simple horizontal shaft indexing and supports:

• Face drilling in the vertical position.
• Angled hole patterns.
• Slots positioned around a tapered or angled component.
• Indexed milling on inclined workpieces.
• Horizontal shaft and arbor machining.

After positioning, securely lock the head and confirm its alignment relative to the milling-machine axes.

MT2 Spindle for Compact Tooling

The dividing spindle has an MT2 internal taper and a 0.709″ through hole. The smaller MT2 interface differentiates the BS-0 from the larger MT3 Vertex BS-1.

The MT2 taper accepts compatible centers and tooling suited to the size of the dividing head. The through hole can provide clearance for suitable workholding components, subject to the dimensions of the complete setup.

Adjustable Tailstock Included

The included adjustable tailstock allows shafts, gear blanks and longer components to be supported between centers. This reduces unsupported workpiece length and can improve setup stability during indexed milling.

Between-centers support is useful for:

• Small shaft flats.
• Keyway arrangements.
• Gear blanks mounted on arbors.
• Fluted shafts.
• Multiple features along a cylindrical component.

Align the tailstock carefully with the dividing-head spindle. Use only enough center pressure to support the part without distorting the workpiece or overloading the centers.

Hardened Spindle and Worm Components

The spindle is hardened and ground and is rigidly supported in a tapered roller bearing. The worm mechanism is also hardened and ground to provide smooth rotation and controlled angular positioning.

The construction is designed to offer:

• Good rigidity for its compact size.
• Smooth manual rotation.
• Reduced unwanted spindle play.
• Controlled worm engagement.
• Adjustable backlash through proper maintenance.

Final machining accuracy still depends on the condition of the milling machine, setup rigidity, clean mounting surfaces, correct indexing calculations and operator technique.

No-Thread BS-0 Configuration

This SKU is identified as the Vertex BS-0 No-Thread configuration. Some generic product descriptions incorrectly state that it has a threaded spindle nose.

Do not purchase a threaded chuck adapter based solely on generic BS-series information. Verify the actual spindle face, included backplate and mounting-hole pattern before selecting additional workholding.

The supplied set lists a backplate for installing a compatible three-jaw chuck. Optional Vertex front-mount chuck references include:

• 4″ front-mount three-jaw chuck – SKU 3800-5820
• 5″ front-mount three-jaw chuck – SKU 3800-5821
• 6″ front-mount three-jaw chuck – SKU 3800-5822

These front-mount chucks are designed for applications where rear mounting is not accessible. Confirm the bolt pattern, register, supplied hardware and machine clearance before ordering a chuck.

BS-0 or BS-1: Which Size Is Better?

Choose the Vertex BS-0 when:

• Available milling-table space is limited.
• The workpieces are relatively compact.
• Lower lifting and table weight are important.
• An MT2 spindle interface suits the shop’s tooling.
• The primary requirement is standard direct and indirect indexing.

Choose the Vertex BS-1 when:

• Larger workpieces require additional support and rigidity.
• An MT3 spindle taper is preferred.
• The machine table can support the larger 74 lb assembly.
• More physical capacity is worth the additional table space.

BS-0 or BS-2 Universal Dividing Head?

The BS-0 is intended for direct, indirect and calculated angular indexing. It does not list the change gears and support arms required for differential indexing and synchronized spiral milling.

Select the Vertex BS-2 universal dividing head when the application requires differential indexing, uncommon divisions outside the standard indirect-indexing combinations or transmission of table movement for spiral and helical work.

Technical Specifications

What Is Included?

• Vertex BS-0 semi-universal dividing head
• Adjustable matching tailstock
• Centers
• Drive dog
• Dividing plates
• Backplate for mounting a compatible three-jaw chuck

Chuck notice: A three-jaw chuck is not identified as included. Confirm the included backplate and mounting interface before ordering an optional chuck.

Compatibility Checks Before Ordering

• Confirm milling-machine table dimensions and T-slot spacing.
• Verify table load capacity for the head, tailstock, chuck and workpiece.
• Check available X, Y and Z travel.
• Confirm cutter clearance with the head tilted or vertical.
• Verify the MT2 tooling requirement.
• Confirm workpiece length and tailstock adjustment range.
• Inspect or verify the no-thread spindle face and chuck backplate.
• Check the optional chuck register and bolt pattern.

Frequently Asked Questions

Is the Vertex BS-0 suitable for a small milling machine?

Its compact size and 45 lb shipping weight make it more practical than the larger BS-1 for many smaller machines. The actual table load, travel and clearance must still be verified.

Can the BS-0 be used for gear cutting?

It can index a suitable gear blank for spur-gear cutting. Cutter selection, blank geometry, tooth count and indexing calculations remain application-specific.

Can it perform differential indexing?

Differential change gears are not listed with this set. Select the Vertex BS-2 when differential indexing is required.

Can it perform spiral milling?

No spiral-milling transmission components are listed with the BS-0 set. The BS-2 is the appropriate model for synchronized spiral or helical setups.

Does it have a threaded spindle nose?

This SKU is identified as the BS-0 No-Thread version. Because some copied descriptions contain contradictory information, verify the physical spindle and backplate before purchasing an adapter or chuck.

Does the set include a three-jaw chuck?

No chuck is identified as included. A backplate is listed, and compatible front-mount chuck options are available separately after interface verification.

Add Compact Indexing Capability Without Sacrificing Your Milling Table

The Vertex BS-0 7-1/2″ Semi-Universal Dividing Head gives smaller milling departments a flexible system for gears, flats, slots, hole patterns and between-centers work while keeping table weight and occupied space below the larger BS-1.

Add the Vertex BS-0 to your quote today. Send us your milling-machine model, table dimensions, workpiece size and preferred chuck diameter so we can help verify the complete setup.

Request pricing and compatibility support

Compare Dividing Head Size and Capability

• Browse all dividing heads for milling-machine indexing.
• Need additional workpiece capacity? Compare the Vertex BS-1 10″ semi-universal dividing head with MT3 spindle.
• Need differential indexing or spiral milling? Review the Vertex BS-2 universal dividing head with change gears.
• For compact workholding, consider the Vertex 4″ front-mount three-jaw chuck after confirming the backplate interface.
• For greater gripping capacity, review the Vertex 6″ front-mount three-jaw chuck and verify machine clearance.
• Compare all front-mount chucks for dividing heads and rotary tables.
• For repetitive fixed-position indexing, explore our rotary indexing fixtures and super spacers.