Hand ramming is the oldest and slowest method of making a mould. Hand ramming is adopted for jobbing production where low-quantity requirements or unsuitable size preclude the use of moulding machines. Intermediate stage between the hand and full machine moulding is the production of light moulds on the simple-pattern draw machines where ramming is still manual, although the machine type pattern plate assemblies are employed and the mould is stripped by a hand-operated machine action.
Peg rammers are used for hand-operated compaction of moulding aggregate. Their wedge-shaped end is used to ram the moulding aggregates at the edges of the moulding box and the gaps between the patterns. The other end of the hand rammer is flat, used to ram the flat areas at the top layer of the mould. When ramming, the moulding aggregate becomes denser only around the rammer strike. Individual blows must be therefore directed to gradually ram the entire surface of the mould. The ramming begins using the wedge end of the rammer at the walls of the moulding box, and proceeds around its perimeter gradually towards the centre of the box. A blow presses the layer towards the box wall, while shifting it to the centre. The greater the distance from the impact site, the lower the aggregate compaction, which is due to the friction between the individual grains of the moulding aggregate as they move relative to each other. The mould volume is rammed a layer by layer; an optimum layer thickness ranges between 50 – 10 cm. The course of compaction degree along the height of the moulding box is uniform, and the fluctuations caused by the individual hammer blows are insignificant. The degree of compaction, as well as hardness of the mould, is controlled by the weight of the peg rammer, severity of the blows and their amount at the same place.
The traditional method of compaction by peg rammers relies heavily upon the manual skills in the production of dense moulds. The aggregate flowability is less important than in the machine moulding, since the aim is to localize the effect of each rammer blow. The tendency is thus to use the aggregates of high green strength, in some cases based on the naturally bonded sands. The use of pneumatic hand-operated rammers does not introduce any major change in mould characteristics, although production rates can be greatly increased and labour reduced.