Im the same, I literally just drew the product once and thats it in 3D, felt like that was so little work for 8 marks? Is that all you did?
For hardness I also sort of did the brinell test, but because it was a workshop test rather than an industry one I said that a dot punch and a hammer were used to do it instead of the full machine thing. But I wasnt sure how they would measure the indentation in a workshop so I said a microscope but I dont think they'd have access to that, also put a micrometer but I'm really unsure.
For toughness I accidentally took it as wear resistance, they're so similar so I said that youd rub it with an abrasive and the tougher it is the less that would come off. Spoke about the weight of it being measured before and after. Turns out toughness its its ability to absorb energy without breaking :/ ?
I said about zinc to galvanise it, completley guessed the pressure thing for the wood too - I said it got sprayed with a lot of pressure with a liquid that protects it from insects and rotting etc.
Ahhh you sound like you did well on the tooth brush bit, I just wrote loads of good points rather than any impovements, I said about the grip, being overmoulded, the use of colour to appeal to everyone, the grooves to fit the users fingers, the use of nylon for the bristles to improve comfort whilst still cleaning etc. etc.
So unsure on how I did haha! Good luck to you