Related Clues:

• Render inflexible
• Make tough
• What tuning forks are made of
• Carpenter's tool for a pair
• Mixture of carbon and iron
• Strong building material
• A pair as of game birds
• Support or hold steady
• Met Al at the slippery end of the street
• At the end of the street the twister is so metallic it sounds as if one might pinch it
• Does this give strength to both of them?
• A bit more and one might make the whole of it, by the sound of it
• That's make it fast and go fast at last
• Sounds as if one might pinch what isn't 27 across
• Iron this, if it comes to the pinch by the sound of it, and drive it from the inside