What is the typical bevel angle for a microtome knife?

• A. 27-32 degrees
• B. 3-8 degrees
• C. 15-23 degrees
• D. 40-50 degrees

Answer: (A)

The bevel angle describes how steep the ground edge of the microtome knife is, which directly affects how sharp and how durable the edge will be during sectioning. For paraffin-embedded tissue, you want a edge that is sharp enough to cut cleanly but sturdy enough to resist chipping under repeated cuts. A typical microtome knife is ground to a bevel around 27 to 32 degrees, striking that balance between sharpness and edge life. If the angle were much smaller, the edge would be too delicate and prone to chipping or dulling quickly. If the angle were much larger, the edge would be too blunt, making it harder to produce thin, clean sections and requiring more force, which can damage the tissue. Therefore, 27–32 degrees is the standard range that provides reliable, high-quality microtomy.