The tier 6 Japanese heavy tank O-I is the first true “heavy tank” in the Japanese heavy tank branch in the sense that it has the armor to withstand a beating. At tier 6 the O-I’s armor uses a combination of thickness, angling, and deception to protect the tank from damage. The armor is also above average across the front, sides, and rear of the tank especially when angling is taken into account. This guide will outline World of Tanks O-I weak spots by breaking down the armor into different sections based on effective armor values. Using this guide you will learn frontal, side, and rear weak spots for the O-I heavy tank in World of Tanks.
Frontally the O-I’s is above average but not terribly difficult for it’s peers to penetrate if they aim at the small green/yellow areas. The orange areas have a maximum of 173mm effective armor while the small green hole next to the gun has zero armor. The O-I’s frontal armor strength comes from it having its strongest armor located on the frontal upper and lower glacis with a minimal of 212mm effective armor on the lower glacis. Most tanks have their weakest frontal armor found on the lower glacis and until the masses learn that the O-I has a very strong lower glacis O-I drivers will benefit from this common knowledge. The other areas above 212mm are the edges of the hatches found on the two frontal turrets and also the commanders hatch on top of the main turret. Around the gun is extremely difficult to penetrate, especially with HEAT, due to their being spaced armor located very far out from the turret and it having extremely tough armor values.
Avoiding the areas highlighted in red is doable if you aim properly and remember to avoid the common lower glacis weak spot. The yellow areas have either 150mm effective armor or just above while the orange areas are closer to 173mm. For most tier 6 tanks and tanks that will face the O-I these areas are easy to penetrate with non-stock guns if the O-I is not angled.
The side of the O-I is the weakest section of the tank since its armor is thinner than both the frontal armor and the rear armor. The O-I does have a 35mm spaced armor plate that runs along the lower hull and covers the entire lower hull in the process. The track armor that runs behind the spaced armor does cover some of the lower hull which brings the effective armor from 70mm to 110mm but for most tanks facing the O-I this will still be easily penetrated outside of HEAT rounds. The strongest armor on the O-I’s side is situation on the main turret and smaller turrets on the front/rear since these areas have 150mm armor and are angled in some spots. If you stick to firing at the side hull where the armor is thinnest you will have no trouble with dealing with the O-I.
Unlike most tanks the O-I’s rear armor is actually tougher than the side armor and almost beats the frontal armor taking into account overall strength. Unlike the frontal armor the rear armor on the O-I has no “green” areas and the weakest armor highlighted in yellow has a 150mm effective armor rating. Orange areas are closer to 179mm due to them being angled more than the yellow areas. The rear also has several tough areas that have a minimal effective armor value of 205mm found on the large angled plate on the rear hull. The higher values are found on the small sections on the edges of the hatches/small turret.