After making sure that the guide block and the knife are properly set, cover the back of the mold with a thin coating of red lead; turn the disk and mold until the mold passes the knife. If the knife is adjusted properly, it should scrape the lead from the mold. It is not always an easy matter to set a mold knife, taking considerable patience and care because the knife must be set to thousandths of an inch. Cast a slug and measure with the micrometers to make sure the slug is trimmed to the proper height. When measuring the slug for height with micrometers, use a slug 15 picas in length, or one that fills half of the capacity of the mold. Have the regular letter characters cast on the slug.
Metal will adhere to the bottom of the mold if the mold knife is not sharp or properly adjusted. To keep a perfect lockup the bottom of the mold must be kept clean. Mold knives can be resharpened, but as they are shaped to set just so the edge of the knife touches the mold and must not vary, for even .001 of an inch will spoil the adjustment, they should be shipped to the nearest agency to be resharpened.
Be sure the knife is at fault before starting to adjust it.
Mold Banking Strips
The mold banking strips are fastened on the vise, one above the parallel knives and the other one below the bottom end of the knives. These strips prevent the mold from coming in contact with the knives and holds the disk rigid when ejecting the slug, assisting the knives in trimming the slug parallel. The mold slide should advance the proper distance so the mold will just bank against the banking strips when forward for ejecting the slug.
KNIFE BLOCK
At the present time there are two styles of knife blocks in common use, namely: The wedge adjustment block, which allows for a range from 5 to 12 points, inclusive; and the universal knife block which allows for a range from 5 to 36 points, inclusive. These blocks are fastened to the vise frame by two hexagon head machine screws and held rigid by four dowel pins. To remove the block it is only necessary to take out the two machine screws and work the block out of the dowel pin holes. A certain amount of care is necessary not to drop the block or bend the pins.
Trimming Knives
The purpose of the trimming knives is to trim the slugs to the proper size and the sides parallel.
The measurement of a type-founders point is .0138-⅓ of an inch. The measurement of a linotype point is .014 of an inch.