If you want to work on your Big Three Lifts - bench, squat and deadlift, you'll more than likely be using a barbell and weight plates (though a barbell and plates can be used for a multitude of other movements too). As you progress with your strength training, you'll need to keep upping your weights so that you continue to challenge yourself - meaning more plates on the bar.
What are weight plates for?
Weight plates are designed to be used in conjunction with a barbell or spinlock adjustable dumbbells. Because they come in many different weight variations, they can be easily interchanged, making them extremely versatile. Plates vary in size, shape and material depending on what you want to use them for, so it's important to think about the bar you will be using them with and the exercises you will want to do before buying your plates.
What are the different types of weight plates?
Weight plates are available in rubber bumper finish, cast iron or vinyl coated cement. The bar you will use them with and the exercises you want to perform will determine the right plates for you. If you have an Olympic Barbell, you will be able to use any Olympic plates with it. Rubber coated plates tend to be most popular as they offer added protection to both the plate and your floor if they are dropped. Their height also makes them ideal for deadlifts. Tri-grip plates are available in both rubber-coated and cast iron finish, with the handles making them easy to carry. Largely, it comes down to your own preference and budget.
What weight should I buy?
It's a good idea to have a variety of different weights in your home gym so that you can adjust your overall load to the exercise and set you're doing. A standard Olympic bar weighs 20kg, so it's important to take this into account when you think about the weight you will need for your movements. For exercises involving smaller muscle groups, like bicep curls, you'll use less weight, and for larger movements like squats and bench press, you'll likely use much more.