Synchronized Spindle Transfer

February 28, 2012

Synchronization is required for spindle transfer of odd-shaped parts including hex and square stock and for round parts using live tooling on the main and sub-spindles. Without synchronized collets extra programming and cycle time are required to line up the workpiece to properly transfer the part from one spindle to the other.

In most cases (draw-in style collets) a keyway is used to align the collets when inserting it into the spindle. Synchronized collets orient the part to a specified point on the workpiece. Hex and square collets are synchronized to the center of the flat or the corner. Hardinge will provide a high tolerance of within 15′ or ¼°. Still greater tolerance can be achieved when required. Collets for specific machines such as Acme Gridley, Hydromat and other multi-spindle lathes that already have a keyway can be synchronized to the customer’s specifications.

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Multiple part processing with Plate and Cube Rotary Trunnions

February 23, 2012

Equals 4th-axis multi-part production for reduced manufacturing cost.

Plate and cube trunnions are add-on accessories for rotary tables or indexers that will allow multiple part positioning in a tilting, dual-axis set up. The plate has a machineable area on two surfaces with an adjustable centerline to accommodate various part heights. The cube is a solid aluminum block. One end of the plate or cube is supported with a bearing pillow block, while the other end mounts in or on the spindle of the rotary table or indexer. Read More

Click here for Hardinge Rotary Brochure

What is the advantage of using a DIRECT-DRIVE rotary table?

February 20, 2012

Direct-drive technology can advance your company to the next level…high-speed, super-precision parts positioning.  ±3 arc-sec accuracy, ±2 arc-sec repeatability and ±.077 arc-sec resolution is achievable! Hardinge direct-drive rotary table indexers have no mechanical gearing. This means ZERO backlash which permits rapid bidirectional movement. Hardinge has three sizes to fit your machining application. The smaller DD100 is ideal for drill and tap and laser processing. The larger DD200 and DD300 include a spindle clamp and slotted face plate. The A2-5 spindle will accept collets, expanding collets, step chucks, FlexC quick-change collets and power chucks.   READ MORE

Gripping bullets, gun parts and optical lenses

February 15, 2012

This push-to-close style collet and stationary collet will grip a cartridge for either trimming to length or forming of the extractor groove.  The smaller double-angle Erickson-style collet grips a bullet jacket for trimming to length. Hardinge manufactures collets and super-precision CNC turning centers used for turning the bullets, trimming bullet jackets, grooving the shanks of the cartridges and crimping the cartridge to the bullet. More information.


Micro finishes and critical radii prevent marking of the soft materials used to make bullets. Hardinge supplies off-the-shelf and custom collets for firearm, ammunition, optic and paintball gun manufacturers worldwide.  Collets, step chucks, fixtures and custom assemblies hold barrels, firing pins, trigger mechanisms, optical lenses, bullet jackets and cartridges. Call 0116 2869900 or email for more info.

Custom gripping for ALL brands of machines and applications… TURNING, MILLING, GRINDING, SPECIALTY MACHINES, INSPECTION, ASSEMBLY.

Don’t Forget Concentricity

February 13, 2012

As parts get more and more complex, you will see part tolerances get tighter than ever. We’ve all seen the (+ -) .0001” size on a turn or bore, but what about concentricity? Quite often, it’s a call out that’s just plain missed. Catching the spec is one thing, meeting it is another.

Here’s some helpful ideas.

First of all, concentricity starts with “round” features. Remember, you cannot check for concentricity between two journals; maybe the spec is .0003” if one of the journals has .0004” run out in itself.

Second, boring the spindle tooling while positioned in the spindle, especially for the 2nd chucking, is a must. If you’re talking .001”, probably not needed, but if the print calls for .0004” concentricity or less, bore the spindle tooling and your success rate goes up.

Third, for the most demanding concentricity specifications, machine all the critical features together. This trick is pretty well understood in this industry but be careful, it’s not a 100% guarantee. There are a lot of factors that affect concentricity, Example: Balance, tool pressure, excessive part clamping pressures, to name a few….…

Hardinge failsafe 5C collet block improves safety and reduces scrap

February 7, 2012

Parts remain clamped if loss of air occurs when using the Hardinge failsafe collet block (closer). Air is required during setup to receive the part, whether using a single collet block or a sub-plate of multiple blocks. After setup, a unique spring design holds the workpiece with 1,760 pounds of optimum 5C drawbar force. The spring-to-close design provides the opportunity to use pallet shuttles without the need for air or hydraulic lines. If loss of air should occur during the machining process, parts will remain clamped and concentricity will be maintained without downtime, waste or injury.

Modular units can be used vertically, horizontally or in any position for machining or assembly operations. These units will line up on a trunnion plate for fourth-axis, multiple-part machining with a rotary table. Each unit has a 5” square footprint with four mounting holes 4” on-center. A 1/8-27 NPT port is located on the back of the unit for connection to shop air. Maximum operating pressure is 75 psi. Multiple units will connect to a single pneumatic connection, but can have separate valves for controlled workpiece placement during setup. Custom sub-plates, modular setups, valve assemblies and special collets can be provided by Hardinge to meet individual requirements.

Group of three 5C failsafe collet blocks manufactured by Hardinge. Three different gripping methods are shown including a collet, a Sure-Grip™ expanding collet and a step chuck that will accommodate larger part diameters.


The Hardinge thru-hole base design allows coolant and chips to be flushed through, rather than building up. This eliminates the time-consuming process of tearing down and cleaning out the unit, as would be the case with other closed-base designs.

Unlike other collet block manufacturers, Hardinge also produces the collets and step chucks for use in the collet block. Standard Hardinge off-the-shelf 5C collets will hold round parts up to 1-1/16”, hex parts up to 29/32” or square parts up to 3/4”. Step chucks can be used to hold parts up to 6” in diameter. Hardinge Sure-Grip® expanding collets will grip the part internally for ID part sizes up to 3-1/64”. Dead-Length® collets offer exact part length control when machining shoulders and faces. The part locates against the face of the collet, the back face of a stepped hole or the face of the work stop to ensure no longitudinal end movement. Manual chucks will also thread onto the spindle nose. Much of this spindle tooling can be shared with other CNC lathes.

The Hardinge 5C collet block offers peace-of-mind because of the fail-safe design that is built in. This design eliminates the risk of scrapping parts, the danger of parts flying off if loss of air should occur, and eliminates downtime associated with chip buildup. Over a century of workholding experience provides the reliability and matched precision from collet to collet block, along with flexible gripping options. Hardinge offers a large selection of pneumatic and hydraulic collet blocks for operating pressures up to 5,000 psi. Shop online at