To afford means for marking work accurately preparatory to machining it, a marking-off table is provided. Certain measuring and marking tools, and suitable blocks for supporting the piece to be marked, must also be provided.

Fig. 153 shows a small marking-off table made of a ribbed slab of cast iron supported firmly on four posts. The top, sides and ends of the slab are planed smooth and at right angles one to another. The table is placed in a permanent location in the shop, where it is firmly supported, and its top is adjusted accurately horizontal.

Fig. 153 - Marking-Off Table.

For very large work, a table may be made of several slabs placed at or near the floor level and supported on a foundation especially built to hold them level.

Fig. 154. - Chocks of Marking-Off Table.