1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'AND p.product_is_free=0 ORDER BY p.products_sort_order' at line 4
in:
[SELECT p.products_id, p.pitch, p.diameter, p.rotation, pd.products_name, p.products_price, IF(p.diameter=0 AND p.pitch=0,p.products_id,0) AS current_blade_type FROM products AS p INNER JOIN products_description AS pd ON pd.products_id=p.products_id WHERE p.products_type=3 AND p.blade_group= AND p.product_is_free=0 ORDER BY p.products_sort_order]