Loose tool forge - preform calculates one, the computation of preform weight: Forging weight decides according to forging graph computation, burn caustic and technology loss weight to be able to consult the concerned data of free forge and forge of hammer upper mould. Because craft of loose tool forge is commonly used at in small plant, medium pre production, craft change is diversiform, so preform weight is normally first via shew computation, use method trying forge to decide again. Should use when having craft of form of flash boil in a covered pot over a slow fire, need to control preform weight strictly, may arise otherwise second (useless) article. Cover the forging of modular stew form, be out of shape in the mould bigger when, cast every time remeasure mould dimension answers before makings, weight of preform of check and ratify. 2, the craft of forge of choice loose tool of preform diameter and preform dimension are concerned. When be like figuration throwing a model, preform diameter should is equal to commonly or be more than forging slightly the biggest diameter. If do not have appropriate preform, can increase batch long or Dui roughcast foreword, loose tool is in more medium or small factory (workshop) production, forging sort is various, storehouse material norms is very difficult all ready, often appear capacity ability is used, material jackleg circumstance, have cannot press craft best choose. The following principle can offer reference: The forging that 1) gives priority to to Dui thick figuration, right long way is in than answering (0. 8 ～ 1.
0) and (2.
0 ～ 2.
Between 5) , such facilitating cut next material and do not arise when Dui is thick fore-and-aft bend. The forging that 2) gives priority to to growing figuration in order to dial, preform diameter and dial chief share place to need length to be more than than answering 0.
3, dial face of long back end to produce sunken heart otherwise. Dui of ministry of 3) play a game of chess is thick forging, preform diameter should is equal to or be less than slightly (dimension of diameter of ministry of lever of forging of 5nnn) of about 1 ～ . CNC Milling