Seems highly unlikely to me. Fracture toughness results tend to be very sensitive to specimen dimensions. See: 

https://en.wikipedia.org/wiki/Fracture_toughness#Fracture_toughness_testing_methods 

Please see:-  these may be helpful.

1) Comments on ‘‘Measurement of the microstructural fracture toughness of cortical bone using indentation fracture’’, J.J. Kruzic et al., Journal of Biomechanics 41 (2008) 1379–1380

2) "Measurement of mechanical properties by ultra-low load indentation", G.M. Pharr, Materials Science and Engineering A253 (1998) 151–159.

3) "Measurement of Fracture Toughness in Thin Films and Small Volumes Using Nanoindentation Methods", G. M. Pharr, D. S. Harding, W. C. Oliver, Mechanical Properties and Deformation Behavior of Materials Having Ultra-Fine Microstructures, NATO ASI Series Volume 233, 1993, pp 449-461.

4) "Investigation Of Fracture Toughness Of Calcium Phosphate Coating Treated Onto Ti6A14V Substrate", İbrahim Aydın et al., 3rd International Symposium on Sustainable Development, May 31 - June 01 2012, Sarajevo.

5) http://cdn.intechopen.com/pdfs-wm/16971.pdf: "Fracture Toughness Determinations by Means of Indentation Fracture", Enrique Rocha-Rangel.

6) "A Critical Evaluation of Indentation Techniques for Measuring Fracture Toughness: I, Direct Crack Measurements", G. R. ANSTIS et al., Journal of the American Ceramic Society, Vol. 64, No. 9, September 1981, pp.533-538

@Phaniriaj C - many thanks for the interesting and useful references. It still seems likely to me that fracture toughness results are very sensitive to test dimensions. Interested to know if someone has made and published the extent to which results for macro-scale toughness measurements correlate with those for e.g. nano-indentation. 

Thanks alot  @ A.U  Daniels @Phaniriaj C @Braj Krishna  i will study and if have any query will get back to you,...

Phaniriaj C this link is not working

(http://cdn.intechopen.com/pdfs-wm/16971.pdf: )

can you plz provide me the pdf file

1) Prof. A.U. Daniels/Dr. Abdul Basit : I have not worked in this area. Since I work on mechanical behavior (mainly creep, tensile and hot deformation at high strain rates),  I have some interest and I have come across a few references:- please see whether they are helpful: (a) "Reliability of Ceramics Fracture Toughness Measurements by Indentation", S. N. Dub, A. L. Maistrenko, Fracture Mechanics of Ceramics, Volume 10, 1992, pp 109-118. (b) "Comparative study on indentation fracture toughness measurements of cemented carbides", Fjodor Sergejev and Maksim Antonov, Proc. Estonian Acad. Sci. Eng., 2006, 12, 4, 388–398. (c) "Microhardness indentation application and limitation in fracture-toughness evaluation of ceramics", H. Nayeb-Hashemi, C.A Tracy, Experimental Mechanics, December 1991, Volume 31, Issue 4, pp 366-372. (d) "On the Vickers Indentation Fracture Toughness Test", George D. Quinnw and Richard C. Bradt, J. Am. Ceram. Soc., 90 [3] 673–680 (2007). (e) "Evaluation by Vickers indentation of fracture toughness of a phosphate biodegradable glass", J. Cle´ment, P. Torres, F. J. Gil, J. A. Planell, R. Terradas, S. Martinez,Journal of Materials Science: Materials in Medicine, July 1999, Volume 10, Issue 7, pp 437-441.

2) Dr. Abdul Basit: I have not worked in this area (please do not get back to me). I had come across a few references and I thought it may help you. I do not have the pdf. Please try copy and paste: please see if you have access:-  http://cdn.intechopen.com/pdfs-wm/16971.pdf

3) Indentation technique for ductile materials:- (a) "An instrumented indentation technique for estimating fracture toughness of ductile materials: A critical indentation energy model based on continuum damage mechanics", Jung-Suk Lee et al, Acta Materialia 54 (2006) 1101–1109. (b) "An indentation technique for estimating the energy density as fracture toughness with Berkovich indenter for ductile bulk materials", Min He et al, Theoretical and Applied Fracture Mechanics 56 (2011) 104–111.

Prof. A.U. Daniels, as a response to your concerns/query, I think you may contact the well known expert Prof. G.M. Pharr of Oak Ridge National Laboratory, USA, and seek his suggestions/advice in this subject of indentation fracture toughness.

You may also see their recent paper in IOP Publishing:- "An evaluation of the advantages and limitations in simulating indentation cracking with cohesive zone finite elements", K E Johanns, J H Lee, Y F Gao and G M Pharr, Modelling and Simulation in Materials Science and Engineering, 22 (2014) 015011, pp 1-21.

In recent years, indentation method for determining fracture toughness has been discredited. It is recommended to use sharp edge samples. Indentation seems working well for brittle materials like ceramics, questionable if applied to ductile materials.

For ductile materials such as steel, you need to follow ASTM standards. Also yes, the tentative data must be justified to meet its 'real' plane-strain conditions, i.e. the fracture toughness.