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

2. 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

3. 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

4. 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

5. Temporary Joining – Nuts and Bolts1 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

6. 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

7. Educational Power Point by D&T Within Schools
© D&T Within Schools DWS
18/05/2019