Tabella Gola Uni Iso 4755 New! -

Whenever you see a bolt that fits perfectly tight against a machine part, you are looking at the legacy of this 1980s standardization—a small groove that solved a massive industrial friction. ISO-4755-1983.pdf - iTeh Standards

In the world of mechanical engineering, there is a recurring problem with bolts and screws. When you try to screw a bolt all the way into a flat surface, the threads often can't reach the very base of the head because of how the manufacturing tools work. Without a "gola" (the Italian word for "throat" or "groove"), the bolt won't sit flush against the surface. The Problem in the Workshop

In mechanical turning, it is impossible for a cutting tool to create a perfect thread right up to a vertical shoulder without a relief zone. The undercut provides: Tool Clearance: tabella gola uni iso 4755

: Fissato a un valore minimo di 30° rispetto all'asse del pezzo per favorire l'invito dell'accoppiamento. Tabella Dimensionale UNI ISO 4755 (Estratto in mm)

: Distanza minima del fondo gola, calcolata sull'angolo di invito. Whenever you see a bolt that fits perfectly

| Passo (P) | Diametro Gola (dg) h12 (h13)* | g1** (min) | g2 (max) ≈ 3P | r ≈ | | :--- | :--- | :--- | :--- | :--- | | | d - 0,4 | 0,4 | 0,75 | 0,12 | | 0,3 | d - 0,5 | 0,5 | 0,9 | 0,16 | | 0,35 | d - 0,6 | 0,6 | 1,05 | 0,16 | | 0,4 | d - 0,7 | 0,6 | 1,2 | 0,20 | | 0,45 | d - 0,7 | 0,7 | 1,35 | 0,20 | | 0,5 | d - 0,8 | 0,8 | 1,5 | 0,20 | | 0,6 | d - 1,0 | 0,9 | 1,8 | 0,40 | | 0,7 | d - 1,1 | 1,1 | 2,1 | 0,40 | | 0,75 | d - 1,2 | 1,2 | 2,25 | 0,40 | | 0,8 | d - 1,3 | 1,3 | 2,4 | 0,40 | | 1,0 | d - 1,6 | 1,6 | 3,0 | 0,60 | | 1,25 | d - 2,0 | 2,0 | 3,75 | 0,60 | | 1,5 | d - 2,3 | 2,5 | 4,5 | 0,80 | | 1,75 | d - 2,6 | 3,0 | 5,25 | 1,00 | | 2,0 | d - 3,0 | 3,4 | 6,0 | 1,00 | | 2,5 | d - 3,6 | 4,4 | 7,5 | 1,20 | | 3,0 | d - 4,4 | 5,2 | 9,0 | 1,60 | | 3,5 | d - 5,0 | 6,2 | 10,5 | 1,60 | | 4,0 | d - 5,7 | 7,0 | 12,0 | 2,00 | | 4,5 | d - 6,4 | 8,0 | 13,5 | 2,50 | | 5,0 | d - 7,0 | 9,0 | 15,0 | 2,50 | | 5,5 | d - 7,7 | 11,0 | 17,5 | 3,20 | | 6,0 | d - 8,3 | 11,0 | 18,0 | 3,20 | *NOTA: * = h12 fino al diametro di filettatura di 3 mm. ** = g1 min. sull'angolo minimo di 30°.

In the world of mechanical fastening and threaded connections, precision is not just a metric; it is a safety requirement. When dealing with hexagon head bolts and screws, one of the most overlooked yet critical geometric features is the (often translated as the "undercut" or "fillet groove"). Without a "gola" (the Italian word for "throat"

(Diametro della gola) : Il diametro minimo del canale. Si calcola sottraendo un valore fisso al diametro nominale del filetto (es.