Ključ viljuškasti dvostrani, za električare

Never use an extension or any form of lever to increase the leverage of a wrench.

Don't use them to free a rusted nut or to finally tighten such a nut.

The nut must always be fully seated before use.

Never use a hammer on wrenches.

Never expose any wrench to excessive heat, which may change the hardness and metal structure and ruin the tool.

Wrenches should not be ground to change their shape.

Don't use a wrench which has been damaged and weakened by being bent, cracked or severely worn.

Use only hand force, never use any form of lever to increase the leverage.

Select a wrench whose opening exactly fits the chosen nut.

Always pull rather than push and always maintain a proper stance with your feet firm to maintain your balance.

Periodic inspection of hand tools by competent personnel is a safety must.