Many 45 RPM records have a small hole in the center to fit onto the record player and stay in place. Other 45s were produced with a large round hole punched out of the center that required a plastic insert to be used in place.
Why is there a difference?
There are several schools of thought as to why large holes were punched out for 45s typically sold in countries like the United States, Canada and others.
Let’s go over each popular theory.
Higher RPM produces damage to the small hole
45 RPM records rotate at a speed of 45 revolutions per minute which means when you started the record player, it went from dead stop to 45 RPM quickly. The small hole of the 45 could get damaged and warped from the torque which made it difficult to play the record over time.
So a larger hole was punched in the center of the 45 and a hard plastic adapter was placed inside the record instead. You could buy plastic inserts at record stores when you needed one.
Some record players came standard with a hard plastic disc that you could use. Since the plastic inserts were interchangeable with any 45 that needed to use it, you only required 1 insert for your record players. You just swapped it out as needed when you played each 45.
But the 78 record rotates at a far higher speed than the 45, so why wouldn’t the 78 record face the same problem?
78 records were bigger, thicker, harder and were initially made of shellac. 45s are made from vinyl which is softer.
In other words, the hole in the center of the 78 was made with harder more durable material and wouldn’t have faced this problem.
Small holes made 45 records difficult to use in jukeboxes
Another theory is that when used in jukeboxes which was the first major use of 45s, these lighter smaller records had trouble being stacked and placed onto the record player for playing. The 78s that were previously used in jukeboxes were larger and heavier and didn’t have this problem.
A related theory was that the small hole in the center of the 45 could get damaged with repeated use of the record so cutting the larger hole and simply designing the jukebox with a permanent insert was a better idea.
Plus, the machine could be less precise when placing a record down on its player with a larger hole to deal with.
A larger hole created more product differentiation
Another theory is perhaps the simplest one. The 45 record was designed and marketed first by RCA Victor in 1949 to compete with the popular 33 1/3 RPM record player that had been released one year earlier by Columbia.
The funny part is that the 33 1/3 record itself was actually designed by RCA in 1931 but they weren’t able to successfully commercialize it.
It was Columbia’s idea to sell the record player to consumers that turned the 33 1/3 record into a success, just not for RCA.
So the theory is that RCA simply decided to make a record that was smaller and that looked different than the 33 1/3 size record and the punched hole in the middle certainly accomplished that.
So RCA – the story goes – designed the 45 RPM record to look different and spin faster than the 33 1/3 RPM record they also created but weren’t able to cash in on, just to make the two records completely incompatible.
Larger holes used less material to make
Another theory is that by punching out a hole in the center of the record, RCA would use less vinyl for each record they made. Less vinyl = lower costs for them.
If the center of the 45 was made with another substance, you’d be using less of that too so whatever the material, the large hole in the center meant using less of it.
When producing millions of records, it could translate to big savings since the cost of the plastic insert adapter was borne by the consumer, not RCA.
Summary
Whatever the actual reason, when your 45 comes with a large hole punched in the center, a round adapter or insert is used which is typically made of hard plastic to get around this. The adapter is placed inside the 45 before playing it to hold the record in place on the turntable. The adapter can be removed as needed and put in another record so in theory you only need to keep one adapter at a time.
Record players often came equipped with their own round, hard plastic adapter to use on 45s, too.
Whatever the reason, any record player that is capable of playing 45 RPM records can handle ones that have a small hole or larger punched hole just fine.
And if you’d like a history of the 78, 33 1/3 and 45 RPM records and why they exist, you can click here to read my article on that.