Round Tip is the standard tip provided unless other wise specified. It can be used in an open atmosphere, in a thermowell, in a liquid or air, and high pressures .
Flat Tip reduces the amount of “sheath” material at the tip of the probe, which can potentially affect the response time, less mass for thermal conduction into the thermocouple junction.

Drill Point Tip (118 deg tip) allows more of the tip surface to be in direct contact with the surface area of a hole, which normally has been “drilled” to the depth required, as opposed to being milled flat at the bottom.

Needle Tip is shaped to a fine point similar to a sewing needle. This facilitates the sensor tip to be inserted into an object for temperature measurement such as food processing, monitoring “skin” temperature on automobile tires at a test track. Not available in diameters below 1/16”.

Reduced Tip sensor for 1/8” reduced to 1/16”(reduced section is 3/8” to 1.0”) allows the “ruggedness” of the 1/8” diameter while giving the fast response of a 1/16” diameter probe. Alternative to a swaged reduced tip is a “step down” version of the reduced tip. This is facilitated by brazing or welding (depends on the diameter) a smaller diameter “MgO” thermocouple inside a larger diameter tube. This again allows the support or ruggedness of the larger diameter while maintaining the fast response of a smaller diameter sensor.

Exposed Tip is recommended where fast response is desired, and corrosive conditions are nonexistent. Commonly used in air and gas applications. The thermocouple wires are butt welded together and the insulation sealed against liquid or gas penetration into the magnesium oxide insulation. The normal exposed length is equal to 1 ½ times the diameter of the probe, it is not available in 0.010” diameter.