Machine parts are manufactured in India according to design given by Indian manufacturers. These parts are made with dimensions or design in accordance with the Indian Standards, while the machine components manufactured in rest of the world are manufactured according to their own standards and/or international standards. For large machining, Indians import small machine parts. As these parts are manufactured in other countries, they are not manufactured as per the Indian standards. ISO standards were set up with the use of all countries' standard designation. According to the manufacturing requirement, usually these two standards, viz., Indian and ISO standards, are used. There is nothing like that the standards out of these are wrong.
Contents
Differences in the two systems
1. Indian standards give the standard principles in a generalized form, i.e., it gives principles for dimensioning any drawing, whether it is a machine-part or assembly of parts. Whereas, the ISO Standards give a perfect set of standard codes to be followed while dimensioning the drawing (separate rules for part drawing and assembled drawing).
2. Indian standards are broader in concept, i.e., they give the common standards for designing as well as the manufacturing of the machine component. On the other hand, in ISO standards there are individual different rules for the designing purpose and for the manufacturing purpose.
3. Indian standards are used only in India, while ISO standards are internationally accepted.
4. Manufacturers in India manufacture the machine components as per the Indian standards only. But this creates a problem in export and of components as the components manufactured in other countries are as per either the standards of their own country or ISO standards. Hence, we conclude that there are some differences in Indian and ISO standards.
5. Components manufactured in accordance with the Indian standards are very less viable to meet with imported components; the components of ISO type are very much likely to be met with any component, manufactured anywhere in the world. This is because ISO standards are established by taking into consideration the standards of all the countries in the world.
Symbols of Geometric Tolerances as per ISO Standards
Notes:
- When applied to a feature-of-size.
- Can also be used as a form control without a datum reference.
- When a datum feature-of-size is referenced with the MMC modifier.
- When an MMC modifier is used.
- Automatic per rule #3.
- The symmetry symbol's characteristics were not included in the version of the chart that this chart is derived from. The symmetry symbol was dropped from the Y14.5M standard around 1988 and re-added around 1994. (It's been speculated that it will be re-dropped the next time the standard is revised.)
Notes:
- The symbol is not part of the 1994 version. See para. A5, bullet 3. Also para. D3. Also, Figure 3-8.
- The symbol appears in the 2009 version of the standard, and refers to unequal profile distribution.
- All the symbols above are used in a feature control frame to specify a feature's description, tolerance, modifier and datum references.
Datums and datum references
A datum is a theoretical ideal plane, line, point, or cylinder. A datum feature is a physical feature of the part identified by a datum feature symbol and corresponding datum feature triangle, e.g.,
These are then referred to by one or more datum feature reference which indicate measurements should be made with respect to the corresponding datum feature and may be found in a datum reference frame.
ISO valve standards
ISO 683-15:1992
Heat-treatable steels, alloy steels and free-cutting steels; part 15: valve steels for internal combustion engines
ISO 4126-1:2004
Safety devices for protection against excessive pressure - Part 1: Safety valves
ISO 4401:1994
Hydraulic fluid power - Four-port directional control valves - Mounting surfaces
ISO 4411:1986
Hydraulic fluid power; Valves; Determination of pressure differential/flow characteristics
ISO 4422-4:1997
Pipes and fittings made of unplasticized poly(vinyl chloride) (PVC-U) for water supply - Specifications - Part 4: Valves and ancillary equipment
ISO 5208:1993
Industrial valves; pressure testing of valves
ISO 5209:1977
General purpose industrial valves; Marking
ISO 5210:1991
Industrial valves; multi-turn valve actuator attachments.
ISO Pipe Standards
ISO 7-1:1994-05
Pipe threads where pressure-tight joints are made on the threads - Part 1: Dimensions, tolerances and designation
ISO 7-2:2000
Pipe threads where pressure-tight joints are made on the threads - Part 2: Verification by means of limit gauges
ISO 49:1994
Malleable cast iron fittings threaded to ISO 7-1
ISO 228-1:2000
Pipe threads where pressure-tight joints are not made on the threads - Part 1: Dimensions, tolerances and designation
ISO 228-2:1987
Pipe threads where pressure-tight joints are not made on the threads; Part 2 : Verification by means of limit gauges
ISO 264:1976
Unplasticized polyvinyl chloride (PVC) fittings with plain sockets for pipes under pressure; Laying lengths; Metric series
ISO 265-1:1988
Pipes and fittings of plastics materials; fittings for domestic and industrial waste pipes; basic dimensions: metric series; part 1: unplasticized poly(vinyl chloride) (PVC-U)
ISO 392:1986
Asbestos-cement pipe fittings for building and sanitary purposes
ISO 580:1990
Injection-molded unplasticized poly(vinyl chloride) (PVC-U) fittings; oven test; test method and basic specifications
ISO 727-1:2002
Fittings made from unplasticized poly(vinyl chloride) (PVC-U), chlorinated poly(vinyl chloride) (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Part 1: Metric series
ISO 727-2:2002
Fittings made from unplasticized poly(vinyl chloride) (PVC-U), chlorinated poly(vinyl chloride) (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Part 2: Inch-based series
ISO 881:1980
Asbestos-cement pipes, joints, fittings/sewage/drain
ISO 1179:1981
Pipe connections, threaded to ISO 228/1, for plain end steel and other metal tubes in industrial applications
ISO 1635-2:1987
Seamless wrought copper and copper alloy tube
ISO 1651:1974
Tube drawing mandrels
ISO 1684:1975
Wire, bar and tube drawing dies; Specifications
ISO 2016:1981
Capillary solder fittings for copper tubes; Assembly dimensions and tests
ISO welding standards
ISO 3677:1992
Filler metal for soft soldering, brazing and braze welding—Designation
ISO 5187:1985
Welding and allied processes—Assemblies made with soft solders and brazing filler metals—Mechanical test methods
ISO 10564:1993
Soldering and brazing materials—Methods for the sampling of soft solders for analysis
ISO 15614-10:2005
Specification and qualification of welding procedures for metallic materials—Welding procedure test—Part 10: Hyperbaric dry welding
ISO 18279:2003
Brazing—Imperfections in brazed joints