https://www.rockislandauction.com/riac-blog/inspecting-your-japanese-sword
In contrast to the traditionally permanent assembly of a rapier or cavalry sword, Japanese swords are made so the end user can easily take them apart. The hilt of a katana or wakizashi is typically secured with one or two pins or, in later swords, bolts. Before attempting to draw the sword, check that this pin is in position and secure. Failure to do this could result in pulling off the hilt and leaving the blade behind, or worse, drawing the sword only to have the blade fall out. Additionally, refrain from any sharp or swift movements of the sword until confident that everything is together, properly secured, and appropriately tight.
Typical Japanese sword and sheath, or saya.
Japanese swords are often found in a sheath (or saya), which is typically constructed from two pieces of wood shaped to fit the blade, glued together with a seam running parallel to the sword's edge and spine. Some might have additional leather coverings, but this is not often a "load bearing" component, in contrast to common American swords. Due to this construction, there is a real and present danger of the sheath splitting along this edge when attempting to withdraw the sword or during accidental rough handling.
For safety, ensure that a personal space bubble is clear of spectators (lest one deliver a swift elbow to an overly curious face when a stuck blade suddenly loses friction), hold the sword oriented in an edge-up posture, and grip the sheath from the bottom, being careful not to wrap any fingers around the top; this will keep any fingers out of harm's way in event of a sheath failure. By keeping the edge upright, chances of the skin of the blade being rubbed against unseen debris trapped in the sheath can be reduced. If the sword does not come out with gentle pressure, check for a retention device; these are sometimes seen on military-pattern swords and can be disengaged with a spring-loaded button immediately below the guard.
What To Do About Oil?
Once out, it is not uncommon to find protective grease or other storage residues on a Japanese sword. While not the "according to Hoyle" traditional way to store them, coating the blades in grease or oil was the best method known to those bringing the swords home to the States after the Second World War. Other times, there will be a light coating of oil on the blade, which is a more proper style of protection. Even if these coatings are not removed, a basic check of the blade can still be completed. If humidity is a problem in storage spaces and regions, consider leaving the oil where it is.
Lot 255: Japanese Sword
While less prone to flexing than Western swords, it is still worthwhile to check; sword in hand (with space bubble appropriately cleared), extend the tip towards an available light source, edge up, and look down the edge of the blade. Any significant deviation in the line of the blade is more noticeable in this orientation than attempting to view from the side, and any serious chips in the edge can be seen in any odd reflections of light. Edge and tip chipping is a common issue with Japanese swords due to the very high hardness (at the cost of ductility) of the materials used in that section of the blade. While unsightly, these chips are part of the history of that particular blade.
