H7ToleranceChart

Interference: The difference before mating between the size of the hole and the size of the shaft when the diameter of the shaft is larger than the diameter of the hole.

Upper deviation: The difference between the maximum limiting size and the corresponding nominal size of a feature.

J6ToleranceChart

ISO 286 establishes a system for tolerances to be used for linear sizes of features of cylinder and two parallel opposite surfaces. It provides a standardized selection of tolerance classes for general purposes from amongst the numerous possibilities. The main intention of this system is the fulfilment of the function fit.

Want to add some deck rigging to an '04 carbon fiber Easy Rider Dolphin. Any cautions/techniques best to prevent cracks/chips? Thanks, Rick

M6tolerancechart

GD&T A means of dimensioning and tolerancing a part with respect to relationship and function of that part. GD&T is used to define how a part feature relates the other part features in the same part or in a mating part; it’s a way to dimension and tolerance with respect to part’s function, the way it works.

Designation of the tolerance class: The tolerance class shall be designated by the combination of an upper-case letter(s) for holes and lowercase letters for shafts identifying the fundamental deviation and by the number representing the standard tolerance grade. For example H7 tolerance class for holes and h7 tolerance class for shafts.

ISOToleranceChart for holes and shafts PDF

use a backer …… on the underside to secure fastners through . Hardwood block larger than the footprint of the thing your attaching . This spreads the load that gets applied to the attachment … called a backer .

In generalI don’t like putting extra holes in a hull and carbon fiber presents additional challenges as the cloth can snag and separate. One statement I can quote is as follows: “For the best results for drilling holes in to fibre glass or carbon fibre use a diamond coated drill bit these are much sharper and stay sharper which means they cut the fibres easily without dragging them.” I assume the newer the bit, the cleaner it will be going through the hull. Rick

Hole and shafttoleranceChart

Transition Fit: A fit type where clearance or interference can exist between assembled parts depending on tolerance conditions.

Fit: Relationship between an external feature of size and an internal feature of size (the hole and shaft of the same type) which are to be assembled.

Lower deviation: The difference between the minimum limiting size and the corresponding nominal size of a feature.

On one or both sides to minimize chipping. I've had good success with both regular bits on a drill and the super high-speed drills with a RotoZip tool. The latter goes through like the hull is butter - good for cutting larger areas such as installing a new hatch, or just making a clean hole. If you need to drill a wide hole, either use a special bit that has its own mini-pilot-hole drilling tip or start with a small bit then go up the size with bigger bits... Depending on what you are attaching you can use wide rubber-faced stainless washers and a nut on the inside, not just the nut, so you have more surface area to pull against. Or use the self expanding rubber-coated bolts (forgot the name) - they work really well for deck rigging that will not see too much stress and do not require access to the underside of the deck. Of course, you can go fancy and use fittings that are glassed-in. And there is the option to glue on the outside carbon fittings - no drilling required and they are strong and light. Places like CLC boats sell them or make your own.

Clearance: The difference between the size of the hole and the size of the shaft when the diameter of the shaft is smaller than the diameter of the hole.

M6tolerancefor Shaft

ISOToleranceChart

Fits and tolerance calculator for shaft and hole tolerance calculation according to ISO 286-1 and ANSI B4.2 metric standards . The schematic representation of the fit is also drawn by tolerance calculator.

You should get clean holes in carbon or glass laminate with just ordinary, new, sharp high speed bits. Drill speed slow to moderate. Don’t worry about delamination. Though stiff, glass and carbon fibers will shear off easily. The resin will hold the rest together. And I wouldn’t do anything special about the holes, once they’ve been drilled. You don’t need to paint the edges with anything. If you were drilling glass/Kevlar, a little bit more attention might be needed, because Kevlar fibers are very tough, and if your drilling were to get ham-handed, those tough fibers might pull loose of the resin near the hole. But even then, it wouldn’t amount to anything. Kaz of Millbrook builds S-glass/Kevlar boats, drills them to lace float bags, and everything holds up just fine.

The need for limits and fits for machined workpieces was brought about mainly by the requirement for interchangeability between mass produced parts. In order that fit function could be satisfied, it was found sufficient to manufacture a given workpiece so that its size lay within two permissible limits, i.e. a tolerance, this being the variation in size acceptable in manufacture while ensuring the functional fit requirements of the product. Similarly, where a specific fit condition is required between mating features of two different workpieces, it is necessary to ascribe an allowance, either positive or negative, to the nominal size to achieve the required clearance or interference.

1000’s of holes drilled ZERO problemsput the bit where you want the hole, don’t let it slip and pull the trigger. Its done. No need to think after that. Now if dealing with globbed on gelcoat or even if you not sure … REVERSE the bit through the gelcoat, when color change, forward bit as above … done.

The tolerances defined in ISO 286-1 are applicable to size range from 0 mm to 3150 mm but there are exceptional cases defined in the standard which depends on tolerance selection. If the calculation results given by the tolerance calculator are "---", then this means the input parameters are not applicable according to ISO standard.