Thread type: Rd - Knuckle thread DIN 405

Overview table, specification and cross section

The round thread is a special thread form that can be designed both as a movement thread (or sliding thread) and as a fastening thread. The values in the Rd thread table are based on DIN standard 405. The round thread according to the Rd thread table is particularly notable for its unusual profile. It is completely rounded and does not have any hard edges. As a result, the round thread according to the Rd thread table is particularly resistant to dirt and damage. It is therefore the first choice when it comes to use in mechanically demanding and dirt-prone working environments. The round thread is typically found in brake spindles on railroad wagons, as a coupling spindle or on load hooks. Corresponding to these areas of application, the round thread is often found in large dimensions, as you can clearly see from the Rd thread table.

The Rd thread has a flank angle of 30°. The thread designation is made up of the abbreviation Rd, the nominal dimension in mm and the number of threads per inch. We are therefore dealing here with a combination of metric dimensions and inch pitches. It should also be noted that the profiles for external and internal threads differ according to the Rd thread table. The number of values in the Rd thread table is correspondingly extensive.

Our Rd thread table includes thread sizes from Rd 8 x 1/10" up to an impressive Rd 200 x 1/4". The Rd thread table also contains information on the outer diameter, the diameter of the bolt and the core hole diameter of the nut. All these details are given in mm in the Rd thread table. The pitch of the Rd thread is specified in threads per inch, as is the standard for inch threads. In our Rd thread table, however, we have also converted this information into a metric value for the pitch. This means that you can also work with the corresponding specification in mm if required.

 Major Ø
in mm
preparatory-Ø
in mm
core hole-Ø 
nut in mm
Pitch P
in mm
TPI
Rd 8 x 1/10"8,2545,4605,7142,54010
Rd 9 x 1/10"9,2546,4606,7142,54010
Rd 10 x 1/10"10,2547,4607,7142,54010
Rd 11 x 1/10"11,2548,4608,7142,54010
Rd 12 x 1/10"12,2549,4609,7142,54010
Rd 14 x 1/8"14,31810,82511,1423,1758
Rd 16 x 1/8"16,31812,82513,1423,1758
Rd 18 x 1/8"18,31814,82515,1423,1758
Rd 20 x 1/8"20,31816,82517,1423,1758
Rd 22 x 1/8"22,31818,82519,1423,1758
Rd 24 x 1/8"24,31820,82521,1423,1758
Rd 28 x 1/8"28,31824,82525,1423,1758
Rd 30 x 1/8"30,31826,82527,1423,1758
Rd 32 x 1/8"32,81828,82529,1423,1758
Rd 34 x 1/8"34,31830,82531,1423,1758
Rd 36 x 1/8"36,31832,82533,1423,1758
Rd 38 x 1/8"38,31834,82535,1423,1758
Rd 40 x 1/6"40,42335,76736,1904,2336
Rd 42 x 1/6"42,42337,76738,1904,2336
Rd 44 x 1/6"44,42339,76740,1904,2336
Rd 46 x 1/6"46,42341,76742,1904,2336
Rd 48 x 1/6"48,42343,76744,1904,2336
Rd 50 x 1/6"50,42345,76746,1904,2336
Rd 52 x 1/6"52,42347,76748,1004,2336
Rd 55 x 1/6"55,42350,76751,1904,2336
Rd 58 x 1/6"58,42353,76754,1904,2336
Rd 60 x 1/6"60,42355,76756,1904,2336
Rd 62 x 1/6"62,42357,76758,1904,2336
Rd 65 x 1/6"65,42360,76761,1904,2336
Rd 68 x 1/6"68,42363,76764,1904,2336
Rd 70 x 1/6"70,42365,76766,1904,2336
Rd 72 x 1/6"72,42367,76768,1904,2336
Rd 75 x 1/6"75,42370,76771,1904,2336
Rd 78 x 1/6"78,42373,76774,1904,2336
Rd 80 x 1/6"80,42375,76776,1904,2336
Rd 82 x 1/6"82,42377,76778,1904,2336
Rd 85 x 1/6"85,42380,76781,1904,2336
Rd 88 x 1/6"88,42383,76784,1904,2336
Rd 90 x 1/6"90,42385,76786,1904,2336
Rd 92 x 1/6"92,42387,76788,1904,2336
Rd 95 x 1/6"95,42390,76791,1904,2336
Rd 98 x 1/6"98,42393,76794,1904,2336
Rd 100 x 1/6"100,42395,76796,1904,2336
Rd 105 x 1/4"105,63598,65099,2856,3504
Rd 110 x 1/4"110,635103,650104,2856,3504
Rd 115 x 1/4"115,635108,650109,2856,3504
Rd 120 x 1/4"120,635113,650114,2856,3504
Rd 120 x 1/4"120,635113,650114,2856,3504
Rd 125 x 1/4"125,635118,650119,2856,3504
Rd 130 x 1/4"130,635123,650124,2856,3504
Rd 135 x 1/4"135,635128,650129,2856,3504
Rd 140 x 1/4"140,635133,650134,2856,3504
Rd 145 x 1/4"145,635138,650139,2856,3504
Rd 150 x 1/4"150,635143,650144,2856,3504
Rd 155 x 1/4"155,635148,650149,2856,3504
Rd 160 x 1/4"160,635153,650154,2856,3504
Rd 165 x 1/4"165,635158,650159,2856,3504
Rd 170 x 1/4"170,635163,650164,2856,3504
Rd 175 x 1/4"175,635168,650169,2856,3504
Rd 180 x 1/4"180,635173,650174,2856,35044
Rd 185 x 1/4"185,635178,650179,2856,3504
Rd 190 x 1/4"190,635183,650184,2856,3504
Rd 195 x 1/4"195,635188,650189,2856,3504
Rd 200 x 1/4"200,635193,650194,2856,3504

More knuckle thread on request:
DIN 168-1 knuckle thread for glass containers
DIN 262-1+ 2 knuckle thread for rail vehicles, with clearance and steep flank, pitch 7 mm
DIN 264-1 knuckle thread for locomotive
DIN 3182-1 knuckle thread for respiratory protection and diving equipment
DIN 15403 knuckle thread for hooks and hoists
DIN 20400 knuckle thread for mining

Cross section of Rd thread