Educational Power Point by D&T Within Schools ® Duration 6:38 © D&T Within Schools 2014 DWS 18/05/2019

Temporary Joints – Nuts and Bolts Sometimes when we are joining materials together we don’t want the joint to be permanent, like brazing, soldering, welding or riveting Reasons for this might include: To make maintenance and repair easier To replace broken or worn parts Self assembly by purchaser Items that are too big to get through doors Allowing for modifications and upgrades to take place Allowing for adjustments to compensate for wear Allowing the part to move freely, but still be connected to another part

Temporary Joining – Nuts and Bolts Maintenance and Repair If we can repair things they are more sustainable, because they last longer It is cheaper for the user, than buying new Machinery can be kept in peak condition and therefore be safer Broken parts can be replaced with new instead of having to replace everything We need expertise and skill to make repairs and replace parts – we may need a specialist

Temporary Joining – Nuts and Bolts Many things use screw threads to join them to something else Sometimes a nut and bolt is used, other times the thread is on the component –e.g. spark plug and washing machine pipes Nuts and bolts come in all sorts of sizes and materials We can cut a thread into metal or plastic using taps and dies to join components together

Temporary Joining – Nuts and Bolts 1 2 3 Self Locking Slotted or Castle nut with a split pin Self Locking Nut Spring Washer Nuts can be tightened by hand, a spanner, a wrench or a socket There are three main ways of stopping nuts working loose due to vibration A spring washer exerts pressure onto the head of the bolt or nut preventing it from working loose A split pin goes through a hole in the bolt and the slots in the nut, both ends are then bent around the nut to secure it The bolt cuts a thread into the nylon insert in the nut keeping it secure. N.B. If the nut is removed it should be replaced with a new one to ensure integrity of the fixing, otherwise it could work loose Wing nut can be tightened by hand

Temporary Joining – Nuts and Bolts Tools used to tighten nuts Ratchet handle & socket Grips all 6 corners of nut Need a different socket for each size of nut Do not have to remove socket when tightening due to ratchet Does not slip Ring spanner Grips on all 6 corners of the nut Need a different spanner for each size of nut Does not slip Open ended spanner Grips on two sides of the nut Need a different spanner for each size of nut May slip if a lot of torque is applied Adjustable Wrench Grips on two sides of the nut May be used on any size nut after adjusting Does not grip very firmly due to the play in the thread, so may slip off

Educational Power Point by D&T Within Schools ® © D&T Within Schools 2014 DWS 18/05/2019