GB/T 8844-2026Die casting dies - Technical specifications (English PDF)

1 Scope

This document specifies the technical requirements, the inspection rules and the marking, packing, transport and storage of die casting dies, and describes the corresponding test methods.

It applies to the manufacture of die casting dies.

2 Normative references

The contents of the following documents constitute indispensable provisions of this document through normative reference in the text. For dated references, only the edition corresponding to that date applies. For undated references, the latest edition, including all amendments, applies.

GB/T 191 Packaging - Pictorial marking for handling of goods · GB/T 230.1 Metallic materials - Rockwell hardness test - Part 1: Test method · GB/T 231.1 Metallic materials - Brinell hardness test - Part 1: Test method · GB/T 825 Lifting eye bolts · GB/T 1184-1996 Geometrical tolerancing - Tolerances of form, orientation, location and run-out - Generally tolerances · GB/T 1804-2000 General tolerances - Tolerances for linear and angular dimensions without individual tolerance indications · GB/T 1958 Geometrical product specifications (GPS) - Geometrical tolerancing - Inspection and verification · GB 2894 Safety signs and guideline for the use · GB/T 3177 Geometrical product specifications (GPS) - Inspection of plain workpiece sizes · GB/T 4340.1 Metallic materials - Vickers hardness test - Part 1: Test method · GB/T 4678 (all parts) Die casting die - Components · GB/T 8845 Die - Terminology · GB/T 9969 General principles for preparation of instructions for use of industrial products · GB/T 10610 Geometrical product specifications (GPS) - Surface texture: Profile method - Rules and procedures for the assessment of surface texture · GB/T 13306 Plates

3 Terms and definitions

The terms and definitions given in GB/T 8845 apply to this document.

4 Technical requirements

Structure: the typical structure of a die casting die is shown in Figure 1, in longitudinal and transverse section, with its forty-one numbered items - moving die clamping plate, ejector plate stop block, spacer block, moving die frame plate, bracket, slide guide plate, cylinder, slide, wedge block, fixed die frame plate, movable core, fixed die insert, insert, cavity, gate, runner, sprue, sprue bush, cooling ring, flow guide block, moving die insert, ejector retaining plate, ejector plate, ejector pin, point cooler, stop pin, ejector guide bush, ejector guide pillar, core, moving die venting plate, fixed die venting plate, conformal cooling insert, squeeze pin, squeeze pin bush, partition, guide pillar, latch, guide bush, return pin, support pillar and ejector connecting rod.

5 Test methods

Appearance: the surface quality of the parts is examined visually and the structure of the die is checked against this document and the die drawing; the outer surfaces are examined visually for the anti-corrosion treatment.

Material and hardness: the material quality certificate and the heat treatment inspection report are examined and, where necessary, the chemical composition is analysed. Brinell hardness is measured to GB/T 231.1, Rockwell hardness to GB/T 230.1 and Vickers hardness to GB/T 4340.1.

Geometrical characteristics: linear dimensions are measured to GB/T 3177, geometrical tolerances to GB/T 1958 and surface roughness to GB/T 10610.

Tightness test: the test pressure shall be not less than 0.5 MPa for ordinary cooling circuits and not less than 1 MPa for high-pressure point cooling circuits, or the pressure required by the design; the pressure shall be held for not less than 5 min and the plugs, connectors and other joints shall be examined for seepage.

Safety check: the safety signs and the lifting eye bolts are examined visually.

No-load running test: the die is mounted on a matching die casting machine and run with no load, and every moving mechanism is checked for correct action and for interference, sticking or abnormal noise.

Trial: the equipment used shall be checked to be in good order; before the trial the tests of 5.1 to 5.6 shall be carried out and all items found to conform. The material and grade of the customer's drawing shall be used and the trial run to the process procedure, with the temperature of the poured melt kept to the process requirement. The complete die casting parameters - melt temperature, die temperature, injection speed, pressure, holding time and cooling time among them - shall be recorded and delivered with the die. Once the process is stable, five to ten consecutive parts shall be taken for inspection and checked against the customer's drawing.

6 Inspection rules

Every die shall undergo the works inspection of all the items of Table 8; where the results of all the items meet this document, the die drawing and the technical agreement, the die is judged to conform. Table 8 pairs each item with its requirement and test method: structure (4.1) with 5.1; parts (4.2) with 5.1, 5.2 and 5.3; assembly (4.3) with 5.4 and 5.6; safety (4.4) with 5.5; and stability (4.5) with 5.7.

Where an item does not conform: if it can be reworked, it is reworked and re-inspected and, if it then passes, judged to conform; if it cannot be reworked, it is scrapped; if it does not affect use and the customer agrees in writing, it may be accepted by concession; and if it seriously affects performance or safety, the customer has the right to reject it. Every such decision shall be noted in the inspection record.

Once the manufacturer and the customer have confirmed that the die conforms, the manufacturer issues the certificate of conformity and delivers it with the die.

7 Marking, packing, transport and storage

Marking: a nameplate complying with GB/T 13306 shall be fixed in a conspicuous place on a non-working face and shall carry the product name and the manufacturer's name, the die number, the size specification, the date of despatch and the mass of the die. Safety signs shall comply with GB 2894.

Packing: the die shall be cleaned before delivery and protected against dust, shock, damp and rust, and its movable parts shall be fixed reliably. The storage and transport marks shall comply with GB/T 191. The packing case shall contain the certificate of conformity, the instructions for use and the operation and maintenance manual - the instructions being written to GB/T 9969 - the inspection report, the packing list and the spare parts list.

Transport: the die shall be packed as the transport requires and protected against damp, rain and knocks; it shall be fixed reliably inside the case so that it cannot move in any direction; and it shall be loaded and unloaded by a method suited to the storage and transport marks on the case.

Storage: the die shall be stored indoors in a clean, dry and well-ventilated place, protected against corrosion and not stacked.

A Annex A (normative) Draft angle of the forming parts

Where the draft angle of the forming parts is not shown, the draft forming the inner wall of the casting shall meet Table A.1 and that forming the outer wall shall be half the value of Table A.1.

Draft angle of the inner wall of a die casting (Table A.1), by draft height and casting material - zinc, magnesium, aluminium and copper alloy respectively: up to 3 mm, 3 degrees, 4 degrees, 5 degrees 30 minutes and 6 degrees 30 minutes; above 3 to 10 mm, 2 degrees, 3 degrees, 3 degrees 30 minutes and 4 degrees; above 10 to 30 mm, 1 degree 45 minutes, 2 degrees 15 minutes, 2 degrees 30 minutes and 2 degrees 45 minutes; above 30 to 50 mm, 1 degree 30 minutes, 2 degrees, 2 degrees 15 minutes and 2 degrees 30 minutes; above 50 to 80 mm, 1 degree 15 minutes, 1 degree 45 minutes, 2 degrees and 2 degrees 15 minutes; above 80 to 120 mm, 1 degree, 1 degree 30 minutes, 1 degree 45 minutes and 2 degrees; above 120 to 180 mm, 45 minutes, 1 degree 15 minutes, 1 degree 30 minutes and 1 degree 45 minutes; above 180 to 250 mm, 45 minutes, 1 degree, 1 degree 15 minutes and 1 degree 30 minutes; and above 250 mm, 30 minutes, 1 degree, 1 degree and 1 degree.

Table A.2 gives the draft angle of round cores.