two new types of milling magnets entered the market – magnetic setup blocks and permanent milling magnets.

Magnetic Setup Blocks
The first was permanent electro magnetic setup blocks. As milling magnets turned the workholding industry upside down, so too will permanent electro magnetic setup blocks forever change conventional fixturing.

Permanent electro magnetic setup blocks are available in 110, 220 and 440 volt. A setup block only supports a permanent electro magnetic setup block supports and clamps. Permanent electro magnetic setup blocks combine the holding power of a milling magnet and the flexibility of a setup block into one.

Magnetic setup blocks are the latest advancements in permanent electro milling magnet technology. They are designed to offer greater flexibility than the conventional milling chucks without sacrificing holding force. Previously, mold shops had to purchase a milling chuck of a given size if they wanted to use milling magnets. If the part to be machined was 1/3 of the chuck size, then 2/3 of the chuck went unused. Or if the part exceeded the size of the chuck, there was no means to stretch the chuck for even support. The only option then was to either do it the old way or buy another chuck.

The introduction of magnetic setup blocks gives the shop greater flexibility and profitability because each module offers the same clamping force as a pair of balanced poles on a milling chuck. The bonus is that if a job requires fewer modules, then the remaining modules can be used on another machine – hence there is no wasted magnetic area. Because the modules are permanent electro, one controller can fire infinite setups.

On the other hand, if a larger part needs to be machined, the modules can be spread apart for better distribution of the magnetic force (see Milling on a Magnet for restrictions). Additional modules can be added as needed to increase the coverage area.

Unlike conventional milling chucks, which do not allow for slight movements in pole placement, magnetic setup blocks can be located wherever the best contact area is available. When mounted to a sub-plate that is drilled and tapped on one-inch centers, placement is easy. In fact, a setup on a sub-plate can be moved from a drilling or milling operation to a grinding operation without demagnetizing the modules. The grinder would clamp to the sub-plate and the modules would continue to hold the workpiece.

Permanent Milling Magnets
 The other new item is a permanent milling magnet that offers significant holding power at a reasonable price. Permanent milling magnets made their debut in 2001 and can be 3.5 times more powerful than traditional permanent grinding magnets. They are ideal for small VMCs and knee mills. Because of the magnetic resistance, each set of poles is individually magnetized and is therefore restricted in size. It is believed that using permanent milling magnets will revitalize the use of traditional knee mills. The knee mill is an American standard, but has not been used as often in recent years.

With the introduction of a permanent milling magnet, the knee mill now has the ability to handle larger parts – such as those that overhang the table – and multiple parts. Previously, once a vice was placed on the bed of a knee mill, only one part could be machined at a time, costing much time in setup. A permanent milling magnet does not require electricity and can be easily moved. It also has the ability to utilize top tooling like pole extenders, back parallels and magnetic angles.