Metal fasteners are normally of two kinds. Those producing a permanent bond and those requiring either a releasable or a sliding bond. Because of the nature of the emergency crane the permanent bond type is obviously not what we are looking for. Screws, nuts and bolts, rivets, retaining rings and clamps are examples from what might be suitable. Non-permanent fasteners include quick-release couplers and clamps intended for removal at a specified time and pins, which allow relative movement of fastened parts.
Metal fasteners must be strong to bear significant loads. In many cases they can be manufactured by powder metallurgical or casting techniques. Iron is a constituent of many types of metal fasteners, although titanium increasingly is coming into use in applications where strength must be balanced against light weight. Steel is probably the best material for the pins for its balance of weight and strength and its relatively low cost for amount of material. After research I have found that probably the most cost effective and safe way of fastening is using the Clevis pin type fastening. This does not require the use of hex nuts and does not run the risk of losing 'grip' or thread like a screw or bolt may. I also researched U bolts and hex bolts.
Clevis pin - A clevis pin is also used in the design of different moving vehicles, including cars and trucks. Since the pins provide a means of creating a secure connection between components while still allowing for a small range of movement, they are much less likely to be affected by any types of vibrations from the engine or while on the road. This is especially useful for the crane as no doubt there is bound to be movement of the crane required and small vibrations or shudders should not mean that the fastenings used should fail. Absorption of lateral stress can be achieved using the pin, which in turn can help minimize the potential for wear and tear on the components connected with the use of the device.
Greater design flexibility, and compared to bolted joints and riveted joints, there is less need for machined holes, and additional machined components. and compared to bolted joints and riveted joints, there is less need for machined holes, and additional machined components.
There are fewer stress concentrations associated with these joints and thus increases fatigue resistance for more durable products versus other mechanical fasteners.
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