Magnet field strength measurements
Note:  UL means the upper left corner of the rectangle as it was measured
UR - Upper right, LL - Lower Left, LR - Lower Right and C is Center
Avg is the average of all these 5 readings.
The readings were obtained using a handheld gauss meter with about a 1.5mm dia
Hall Effect probe at the tip.  The measurements were taken using a plastic grid
over the surface for repeatability - its thickness was 1/32".
1 inch Square by 2mm thick - N35
distance in inches	UL	UR	LL	LR	C	Avg
1/32	1450	1100	1380	1560	150	1128
1/8	600	500	380	670	410	512
7/32	380	260	265	310	425	328
5/16	230	200	185	200	350	233
13/32	145	160	120	170	285	176
1/2	130	110	80	125	230	135
19/32	90	95	85	95	185	110
11/16	85	75	75	75	145	91
25/32	65	50	75	65	115	74
7/8	55	55	55	55	90	62
31/32	45	45	45	50	75	52
30mm square x 3mm thick N38
distance in inches	UL	UR	LL	LR	C	Avg
1/32	1600	1510	1600	1640	1070	1484
1/8	695	720	675	830	940	772
7/32	475	460	380	380	800	499
5/16	300	310	260	340	660	374
13/32	220	220	220	220	530	282
1/2	190	180	200	190	420	236
19/32	150	170	160	170	340	198
11/16	120	160	110	130	270	158
25/32	100	110	100	100	210	124
7/8	80	80	80	80	170	98
31/32	70	70	70	80	145	87
1  1/16	65	65	65	65	120	76
1  5/32	60	60	55	60	100	67
1  1/4	50	50	45	45	80	54
Two - '30mm square x 3mm thick N38 - stuck together
distance in inches	UL	UR	LL	LR	C	Avg
1/32	2160	2190	2280	2200	1930	2152
1/8	1100	1170	1200	1160	1680	1262
7/32	650	640	700	600	1410	800
5/16	450	590	500	530	1160	646
13/32	370	390	330	390	930	482
1/2	360	300	310	360	750	416
11/16	210	240	220	230	480	276
7/8	160	170	160	170	320	196
1  1/16	130	130	110	120	220	142
1  1/4	90	100	90	90	150	104
1  7/16	65	80	60	70	110	77
1  5/8	55	55	50	55	80	59
30mm square x 4mm thick N38
distance in inches	UL	UR	LL	LR	C	Avg
1/32	2000	1760	2000	1650	1360	1754
7/32	540	520	520	530	1030	628
13/32	280	280	310	290	680	368
19/32	200	150	220	200	450	244
25/32	150	125	150	140	290	171
31/32	105	95	100	100	190	118
1  5/32	75	80	75	80	135	89
1 11/32	60	55	60	60	90	65
1 17/32	45	45	45	50	70	51
Two - '30mm square x 4mm thick N38 - stuck together
distance in inches	UL	UR	LL	LR	C	Avg
1/32	2680	2440	2420	2550	2110	2440
7/32	820	810	900	820	1620	994
13/32	530	490	510	470	1100	620
19/32	350	340	380	340	720	426
25/32	250	270	240	240	480	296
31/32	190	200	180	190	330	218
1  5/32	150	150	130	140	230	160
1 11/32	110	110	110	110	160	120
1 17/32	90	90	90	90	120	96
1 23/32	75	75	70	70	90	76
2	50	50	50	55	65	54
80mm square by 10mm thick - N38
distance in inches	UL	UR	LL	LR	C	Avg
1/32	2750	2720	2840	2750	970	2406
7/32	1020	1000	1040	1190	990	1048
19/32	400	370	430	420	860	496
31/32	240	260	220	240	670	326
1 11/32	160	190	170	190	500	242
1 23/32	150	140	160	170	360	196
2  3/32	110	120	105	120	260	143
2 15/32	85	90	90	100	200	113
80mm square by 15mm thick - N42
distance in inches	UL	UR	LL	LR	C	Avg
1/32	3320	3030	3320	3320	2010	3000
13/32	910	780	810	920	1660	1016
19/32	620	510	540	610	1460	748
31/32	360	360	350	440	1080	518
1 11/32	260	280	280	330	780	386
1 23/32	230	220	210	260	560	296
2  3/32	170	160	180	220	400	226
2 15/32	150	155	140	190	300	187
4 inch by 5 inch by 1/2 inch thick plate - N38
distance in inches	UL	UR	LL	LR	C	Avg
1/32	3120	3090	3150	3150	520	2606
13/32	900	88	820	880	700	677.6
19/32	550	560	640	660	690	620
31/32	340	410	330	360	650	418
1 11/32	270	270	230	270	560	320
1 23/32	180	210	180	210	460	248
2  3/32	150	160	140	190	370	202
2 15/32	120	140	120	140	300	164
50mm square (2 inch) by 25mm or 1 inch thick - N40
distance in inches	UL	UR	LL	LR	C	Avg
1/32	3980	3810	4020	3860	3970	3928
13/32	1120	1260	1350	1390	2620	1548
19/32	820	860	880	1020	2050	1126
31/32	600	560	590	640	1240	726
1 11/32	400	440	400	430	760	486
1 23/32	280	320	290	320	490	340
2  3/32	220	220	220	240	330	246
2 15/32	170	180	160	170	230	182
2 inch diameter N45 - 1 inch thick
distance in inches	UL	UR	LL	LR	C	Avg
1/32	4270	4380	4150	4340	4320	4292
13/32	1440	1640	1520	1440	2690	1746
19/32	1090	1210	1240	1180	2050	1354
31/32	680	760	710	790	1170	822
1 11/32	450	490	470	480	700	518
1 23/32
2  3/32
2 15/32	160	170	170	170	200	174