I've already asked a question about how to distinguish between Pilkington K and Climaguard glass. The reason was that i'm supposed to be having Climaguard put in my conservatory but its been labelled Pilkington K. The supplier has assured me that i actually have Climaguard and that it was just mislabelled but i'm not entirely certain he was telling the truth. The supplier says that Climaguard has a blue tinge while K glass is more bronze?
Not 100% sure but I think Climaguard is a product of Guardian Industries, an American glassmaker but with manufacturing facilities in Europe inc. the UK. Pilkington is a UK company. I therefore think they are different products but may have a similar specification.