Italian to English Other Furniture / Household Appliances

I hope the moderators will forgive me for putting two words in the question, but in the text they are always related, so it's as if they were a single term (I hope!). They appear in the list of items included in an assembly kit for an undersink cupboard. The full list reads:

spine legno
**tiranti ed eccentrici**
viti e tasselli

Other examples from the text:
Bloccare i tiranti con gli eccentrici
Infilare i due traversi nei tiranti e bloccare con gli eccentrici

Any ideas... thanks, Sarah.