Usually the fork is bolted all the way up the upright.
In most instances, the bolt-on design reduces deflection in the upright of the fork, thus reducing the overall deflection.
The forks can either be bolted on from the front or the back of the carrier.
If bolted from the front, the holes will be counter-bored/sunk to alleviate projection of the bolt heads and damaging product.
Obtaining the correct bolt-hole pattern for each set of forks is very important. If measuring the pattern on-site, it is important to first identify if the bolt pattern is inch or metric. Attachment make and model information is also helpful.
Bolt holes should not be drilled on the outside heel radius. The start of a bolt-hole pattern should begin at a minimum of 6 in. (152.4mm) above the top of the blade.