Choosing the right power hammer depends on many factors. Every individual blacksmith, artist and knife maker will have their own unique, varied techniques and requirements depending on what material they are working with, what they are producing and what they intend to create. Their most commonly used stock size, along with the volume of production they require, are important factors for the individual to consider when looking at what power hammer to utilize.
The most typical response is "bigger is better" because what can be done by an adequate hammer can be done more efficiently and consistently when the hammer is not being pushed to its working limits. If a hammer can move the largest stock you’re working with at its upper limit, and can technically meet your requirements, you should consider purchasing the next larger size hammer to increase performance and reduce wear on the machine. If production is a primary consideration, what an adequate hammer can accomplish versus what can be accomplished using a slightly larger machine is vast, and the fuel and time it saves more than offsets the initial investment, because each size machine offers a considerable jump in forging power!
Opting for a larger power hammer than you initially think you'll need will give you flexibility in the event you find yourself doing larger projects or using bigger stock, and as you become more proficient with the power hammer, its capabilities will become increasingly more useful over time. Essentially, if you choose a smaller hammer, you'll be limited to its specific working range and power. However, by investing in a larger hammer, you gain the versatility to handle a broader range of tasks, effectively covering the functions of a smaller hammer as well. Hence the common response of go big.
There are many other factors to also consider, such as foundation and placement. We recommend 6 inches of reinforced concrete slab for mounting machines with bases, where the more industrial two piece designs will require a more robust concrete base to be poured, which can drastically increase installation costs. You must also consider your available shop or warehouse space, access to single or triple phase 220v power supply, insulation, ventilation and noise considerations. Your neighbors may not appreciate a massive power hammer in small suburban setting, making a quieter smaller machine more attractive.