BORA Tempest Forstner bits are available in sizes from 1/4″ to 2-1/8″ and in sets of 4, 7 and 16 bits. The 7-piece boxed set contains what are probably the most frequently used sizes of Forstner bits: 1/4″, 3/8″, 1/2″, 5/8″, 3/4″, 7/8″, and 1″ bits. Shank diameters range from 1/4″ to 3/8″. Overall bit length is about 3-1/2″. These bits are manufactured in Austria by FISCH Tools who are widely known for their high-quality drilling and cutting tools.

The softwood storage box is very nicely made and each bit has it’s own slot. It’s nice looking and practical – for bit protection, storage, and carrying about the shop.

Similar to most Forstner bits, these Tempest bits are CNC precision ground from high speed steel. I measured all the bit diameters, and found them to be spot-on. The cutting edges are very sharp as are the beveled edges on the chippers. The four-sided center point makes it easy to precisely position the bit for drilling and makes the bit less susceptible to inadvertently jumping about especially if you use them in a power drill.

The holes that I drilled with the bits precisely matched the diameter of the bits, and the rim edges and bottom of the holes were crisp and clean. When drilling shallow holes, up to about 1″ deep for the 5/8″ and larger bits (up to about 3/4″ with the smaller diameter bits) the bits do a good job of clearing chips. Going any deeper, there was a tendency for the holes to plug-up with debris. To be fair, this happens with all the other brands of Forstner bits I’ve used. You can avoid this problem all-together by sinking the bit 1/4″ or so for small bits (1/2″ or so for larger bits), and then pulling the bit out of the hole to allow chips to clear.

The Tempest drill bits do a great job drilling angled holes, overlapping holes, and holes on the edge of boards. Drilling holes on the edge of stock is easier if you clamp the stock to the drill press table – particularly when drilling into short, narrow stock.

I haven’t used these bits long enough to determine whether they will last appreciably longer than other brands of Forstner bits, but over the four week period that I have been exclusively using the Tempest bits in the shop they’re holding up magnificently. The holes they cut are as crisp and clean as the first time I used the bits and they show no signs of dulling.

I find that these bits cut quickly, and leave super clean holes – both rims and bottoms. Used in the drill press (as they typically should be) they feed easily enough and chip ejection isn’t much of a problem, especially if you back-out the bit when drilling deep or wide holes. When drilling multiple holes consecutively I found that the bits didn’t heat up appreciably.

If consistently precise, cleanly cut flat bottomed holes are what you want, then the BORA Tempest Forstner bits are well worth considering.