ASTM 228/A228M-18: Standard for Steel Wire, Music Spring Quality has been released.
Pianos and window springs—they have more in common than one might think. Before the catchy tune performed on a piano can infiltrate one’s consciousness or playlist, music has to actually come from the instrument. What does that have to do with window springs? Both window springs and pianos commonly use steel wires. ASTM 228/A228M-18: Standard for Steel Wire, Music Spring Quality provides guidelines for steel wires.
The steel wire discussed in ASTM 228/A228M-18 is often referred to as music wire. This is because it is best known for its use in musical instruments such as the piano. However, the steel wires covered in ASTM 228/A228M-18 are versatile. Why can the wire used in these two different actions be similar? To answer this, it helps to look at how pianos actually work.
What Makes the Sound in a Piano?
The sound that emanates from pianos comes from vibrating strings (steel wire). The strings are stretched tightly inside the piano. Each key has its own corresponding string or strings. In fact, there are far more strings than keys. While there are 88 keys, there can be anywhere from 220 to 240 strings in a piano. When a key is struck, a hammer hits its corresponding string (or strings), causing it to vibrate.
The frequency of the vibration is what one hears when a piano sounds. The vibration frequency can change based on the string inside the piano and thus so can the sound. For example, if the steel wire being struck is long and thick, the sound will be lower. If the steel wire is shorter and skinnier, the sound of the piano will be high. What doesn’t change is how the wire reacts to the pounding of hammers. It takes it and returns to its original form.
Why Are Steel Wires Used in Both Music and Springs?
Steel strings are useful with music and springs because, though they might often be stretched or struck, the wires still maintain their quality of sound for long periods of time. Steel wires need to be able to endure the pounding of a piano hammer or, as with a window spring, the “repeated loading, stretching, and relaxing.”
What is the Standard for Steel Wire, Music Spring Quality?
ASTM 228/A228M-18 deals specifically with “two types of round, cold drawn steel music spring quality wire, uniform in mechanical properties, intended for the manufacture of springs subject to high stress or necessitating good fatigue qualities.“
ASTM 228 A/228M-18 revises the 2016 edition of the same standard, so it has some changes. They are:
- Sections 2.3, 2.4, and 15.5 have been removed.
- Sections 2, 8.2.1, 11.1, and Table 5 have been revised.
- Section 11.2 has been added.
- Revised the scope of 1.1. to include two types of music wire.
- Replaced obsolete ANSI B32.4 with ANSI B32.100 in section 2.3.
- Accommodated two types of music wire at section 4.1.2 and Note 1 within Ordering Information.
- The manufacturing guidelines for two types of music wire are mentioned and then expounded upon at section 5.3 and Note 2 within Materials and Manufacture.
- So as not to cause confusion at section 10.2 within Workmanship, Finish, and Appearance, the two types of music wire, referred to are kinds of finish instead the previous types of finish.
- Accommodated two types of wire and several kinds of finish in section 14.3 within Certification.
- Corrected Table 7 of Specification A510/A510M corrected to Table 3 of Specification A510/A510M in section 6.3.
ASTM 228/A228M-18: Standard for Steel Wire, Music Spring Quality is available on the ANSI Webstore.